A continuously updated collection of LeetCode solutions, DSA problems, algorithms, data structures, coding interview questions, and programming solutions.
Each problem includes its problem number, title, difficulty, algorithmic pattern, programming language, time complexity, space complexity, source code, and explanation.
- Total Solved: 746+
- Easy: 482+
- Medium: 195+
- Hard: 69+
- Binary Search
- Sliding Window
- Two Pointers
- Hash Map
- Dynamic Programming
- Greedy
- Monotonic Stack
- Backtracking
- Graph & Tree
- SQL / Database
- Math & Logic
| # | Problem | Difficulty | Pattern | Language | Algorithm | Time | Space | Code | Explanation |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Two Sum | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2 | Add Two Numbers | Medium | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 3 | Longest Substring Without Repeating Characters | Medium | Sliding Window | Python | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 4 | Median of Two Sorted Arrays | Hard | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 5 | Longest Palindromic Substring | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 6 | Zigzag Conversion | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 7 | Reverse Integer | Medium | Bit Manipulation | JavaScript | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 8 | String to Integer (atoi) | Medium | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 9 | Palindrome Number | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 10 | Regular Expression Matching | Hard | Dynamic Programming | JavaScript | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 11 | Container With Most Water | Medium | Two Pointers | JavaScript | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 12 | Integer to Roman | Medium | Heap | JavaScript | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 13 | Roman to Integer | Easy | Prefix Sum | Python | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 14 | Longest Common Prefix | Easy | Prefix Sum | Python | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 15 | 3Sum | Medium | Binary Search | JavaScript | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 16 | 3Sum Closest | Medium | Binary Search | JavaScript | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 17 | Letter Combinations of a Phone Number | Medium | Backtracking | JavaScript | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 18 | 4Sum | Medium | Binary Search | C++ | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 19 | Remove Nth Node From End of List | Medium | Fast & Slow Pointers | JavaScript | Floyd Cycle Detection | O(n) | O(1) | Code | Explanation |
| 20 | Valid Parentheses | Easy | Stack & Queue | JavaScript | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 21 | Merge Two Sorted Lists | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 22 | Generate Parentheses | Medium | Stack & Queue | C++ | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 23 | Merge k Sorted Lists | Hard | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 24 | Swap Nodes in Pairs | Medium | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 25 | Reverse Nodes in k-Group | Hard | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 26 | Remove Duplicates from Sorted Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 27 | Remove Element | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 28 | Find the Index of the First Occurrence in a String | Easy | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 29 | Divide Two Integers | Medium | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 30 | Substring with Concatenation of All Words | Hard | Sliding Window | Python | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 31 | Next Permutation | Medium | Backtracking | Python | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 32 | Longest Valid Parentheses | Hard | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 33 | Search in Rotated Sorted Array | Medium | Binary Search | C++ | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 34 | Find First and Last Position of Element in Sorted Array | Medium | Binary Search | Python | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 35 | Search Insert Position | Easy | Binary Search | Python | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 36 | Valid Sudoku | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 37 | Sudoku Solver | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 38 | Count and Say | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 39 | Combination Sum | Medium | Backtracking | Python | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 40 | Combination Sum II | Medium | Backtracking | Python | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 41 | First Missing Positive | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 42 | Trapping Rain Water | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 43 | Multiply Strings | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 44 | Wildcard Matching | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 45 | Jump Game II | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 46 | Permutations | Medium | Backtracking | Python | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 47 | Permutations II | Medium | Backtracking | Python | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 48 | Rotate Image | Medium | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n²) | O(1) | Code | Explanation |
| 49 | Group Anagrams | Medium | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 50 | Pow(x, n) | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 51 | N-Queens | Hard | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 52 | N-Queens II | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 53 | Maximum Subarray | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 54 | Spiral Matrix | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 55 | Jump Game | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 56 | Merge Intervals | Medium | Heap | Python | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 57 | Insert Interval | Medium | Heap | Python | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 58 | Length of Last Word | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 59 | Spiral Matrix II | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 60 | Permutation Sequence | Hard | Backtracking | Python | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 61 | Rotate List | Medium | Two Pointers | C++ | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 62 | Unique Paths | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 63 | Unique Paths II | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 64 | Minimum Path Sum | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 65 | Valid Number | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 66 | Plus One | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 67 | Add Binary | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 68 | Text Justification | Hard | Heap | Python | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 69 | Sqrt(x) | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 70 | Climbing Stairs | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 71 | Simplify Path | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 72 | Edit Distance | Medium | Array / General | JavaScript, Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 73 | Set Matrix Zeroes | Medium | Tree & Graph | JavaScript | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 74 | Search a 2D Matrix | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 75 | Sort Colors | Medium | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 76 | Minimum Window Substring | Hard | Sliding Window | PHP | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 77 | Combinations | Medium | Backtracking | PHP | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 78 | Subsets | Medium | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 79 | Word Search | Medium | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 80 | Remove Duplicates from Sorted Array II | Medium | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 81 | Search in Rotated Sorted Array II | Medium | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 82 | Remove Duplicates from Sorted List II | Medium | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 83 | Remove Duplicates from Sorted List | Easy | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 84 | Largest Rectangle in Histogram | Hard | Monotonic Stack | TypeScript | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 85 | Maximal Rectangle | Hard | Math & Logic | Python | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 88 | Merge Sorted Array | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 94 | Binary Tree Inorder Traversal | Easy | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 100 | Same Tree | Easy | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 101 | Symmetric Tree | Easy | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 104 | Maximum Depth of Binary Tree | Easy | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 108 | Convert Sorted Array to Binary Search Tree | Easy | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 110 | Balanced Binary Tree | Easy | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 111 | Minimum Depth of Binary Tree | Easy | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 112 | Path Sum | Easy | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 115 | Distinct Subsequences | Hard | Dynamic Programming | JavaScript | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 118 | Pascal's Triangle | Easy | Math & Logic | PHP | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 119 | Pascal's Triangle II | Easy | Math & Logic | PHP | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 121 | Best Time to Buy and Sell Stock | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 125 | Valid Palindrome | Easy | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 136 | Single Number | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 141 | Linked List Cycle | Easy | Fast & Slow Pointers | PHP | Floyd Cycle Detection | O(n) | O(1) | Code | Explanation |
| 144 | Binary Tree Preorder Traversal | Easy | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 145 | Binary Tree Postorder Traversal | Easy | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 150 | Evaluate Reverse Polish Notation | Medium | Stack & Queue | TypeScript | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 153 | Find Minimum in Rotated Sorted Array | Medium | Binary Search | C++ | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 154 | Find Minimum in Rotated Sorted Array II | Hard | Binary Search | C++ | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 160 | Intersection of Two Linked Lists | Easy | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 168 | Excel Sheet Column Title | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 169 | Majority Element | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 171 | Excel Sheet Column Number | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 175 | Combine Two Tables | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 176 | Second Highest Salary | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 177 | Nth Highest Salary | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 178 | Rank Scores | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 180 | Consecutive Numbers | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 181 | Employees Earning More Than Their Managers | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 182 | Duplicate Emails | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 183 | Customers Who Never Order | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 184 | Department Highest Salary | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 185 | Department Top Three Salaries | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 190 | Reverse Bits | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 192 | Word Frequency | Medium | Hash Map | Shell | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 193 | Valid Phone Numbers | Easy | Array / General | Shell | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 194 | Transpose File | Medium | Array / General | Shell | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 195 | Tenth Line | Easy | Array / General | Shell | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 196 | Delete Duplicate Emails | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 197 | Rising Temperature | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 202 | Happy Number | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 203 | Remove Linked List Elements | Easy | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 205 | Isomorphic Strings | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 206 | Reverse Linked List | Easy | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 217 | Contains Duplicate | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 219 | Contains Duplicate II | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 225 | Implement Stack using Queues | Easy | Stack & Queue | PHP | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 226 | Invert Binary Tree | Easy | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 228 | Summary Ranges | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 231 | Power of Two | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 232 | Implement Queue using Stacks | Easy | Stack & Queue | PHP | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 234 | Palindrome Linked List | Easy | Two Pointers | PHP | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 242 | Valid Anagram | Easy | Hash Map | PHP | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 257 | Binary Tree Paths | Easy | Binary Search | PHP | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 258 | Add Digits | Easy | Math & Logic | PHP | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 262 | Trips and Users | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 263 | Ugly Number | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 268 | Missing Number | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 278 | First Bad Version | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 283 | Move Zeroes | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 290 | Word Pattern | Easy | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 292 | Nim Game | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 301 | Remove Invalid Parentheses | Hard | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 303 | Range Sum Query Immutable | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 326 | Power of Three | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 338 | Counting Bits | Easy | Binary Search | C++ | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 342 | Power of Four | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 344 | Reverse String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 345 | Reverse Vowels of a String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 349 | Intersection of Two Arrays | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 350 | Intersection of Two Arrays II | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 367 | Valid Perfect Square | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 374 | Guess Number Higher or Lower | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 383 | Ransom Note | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 387 | First Unique Character in a String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 389 | Find the Difference | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 392 | Is Subsequence | Easy | Dynamic Programming | Python | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 396 | Rotate Function | Medium | Bit Manipulation | C++ | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 401 | Binary Watch | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 404 | Sum of Left Leaves | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 405 | Convert a Number to Hexadecimal | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 409 | Longest Palindrome | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 412 | Fizz Buzz | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 414 | Third Maximum Number | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 415 | Add Strings | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 434 | Number of Segments in a String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 441 | Arranging Coins | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 448 | Find All Numbers Disappeared in an Array | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 455 | Assign Cookies | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 459 | Repeated Substring Pattern | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 461 | Hamming Distance | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 463 | Island Perimeter | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 476 | Number Complement | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 482 | License Key Formatting | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 485 | Max Consecutive Ones | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 486 | Predict the Winner | Medium | Dynamic Programming | C++ | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 492 | Construct the Rectangle | Easy | Math & Logic | Python | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 495 | Teemo Attacking | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 496 | Next Greater Element I | Easy | Monotonic Stack | Python | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 500 | Keyboard Row | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 501 | Find Mode in Binary Search Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 504 | Base 7 | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 506 | Relative Ranks | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 507 | Perfect Number | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 509 | Fibonacci Number | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 511 | Game Play Analysis I | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 520 | Detect Capital | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 521 | Longest Uncommon Subsequence I | Easy | Dynamic Programming | Python | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 530 | Minimum Absolute Difference in BST | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 541 | Reverse String II | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 543 | Diameter of Binary Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 550 | Game Play Analysis IV | Medium | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 551 | Student Attendance Record I | Easy | Monotonic Stack | Python | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 557 | Reverse Words in a String III | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 559 | Maximum Depth of N-ary Tree | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 561 | Array Partition | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 563 | Binary Tree Tilt | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 566 | Reshape the Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 570 | Managers with at Least 5 Direct Reports | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 572 | Subtree of Another Tree | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 575 | Distribute Candies | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 577 | Employee Bonus | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 584 | Find Customer Referee | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 585 | Investments in 2016 | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 586 | Customer Placing the Largest Number of Orders | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 589 | N-ary Tree Preorder Traversal | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 590 | N-ary Tree Postorder Traversal | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 594 | Longest Harmonious Subsequence | Easy | Dynamic Programming | Python | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 595 | Big Countries | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 596 | Classes With at Least 5 Students | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 598 | Range Addition II | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 599 | Minimum Index Sum of Two Lists | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 601 | Human Traffic of Stadium | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 602 | Friend Requests II: Who Has the Most Friends | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 605 | Can Place Flowers | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 607 | Sales Person | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 608 | Tree Node | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 610 | Triangle Judgement | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 617 | Merge Two Binary Trees | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 619 | Biggest Single Number | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 620 | Not Boring Movies | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 626 | Exchange Seats | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 627 | Swap Sex of Employees | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 628 | Maximum Product of Three Numbers | Easy | Binary Search | Elixir | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 636 | Exclusive Time of Functions | Medium | Stack & Queue | TypeScript | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 637 | Average of Levels in Binary Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 643 | Maximum Average Subarray I | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 645 | Set Mismatch | Easy | Bit Manipulation | TypeScript | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 653 | Two Sum Iv Input Is A Bst | Medium | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 657 | Robot Return to Origin | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 661 | Image Smoother | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 671 | Second Minimum Node In a Binary Tree | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 674 | Longest Continuous Increasing Subsequence | Easy | Dynamic Programming | Python | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 678 | Valid Parenthesis String | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 682 | Baseball Game | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 693 | Binary Number with Alternating Bits | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 696 | Count Binary Substrings | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 697 | Degree of an Array | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 700 | Search in a Binary Search Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 703 | Kth Largest Element in a Stream | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 704 | Binary Search | Easy | Binary Search | Python | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 705 | Design HashSet | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 706 | Design HashMap | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 709 | To Lower Case | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 717 | 1-bit and 2-bit Characters | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 724 | Find Pivot Index | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 728 | Self Dividing Numbers | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 733 | Flood Fill | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 739 | Daily Temperatures | Medium | Monotonic Stack | TypeScript | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 744 | Find Smallest Letter Greater Than Target | Easy | Prefix Sum | Python | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 746 | Min Cost Climbing Stairs | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 747 | Largest Number At Least Twice of Others | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 748 | Shortest Completing Word | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 762 | Prime Number of Set Bits in Binary Representation | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 766 | Toeplitz Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 771 | Jewels and Stones | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 783 | Minimum Distance Between BST Nodes | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 788 | Rotated Digits | Medium | Binary Search | C++ | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 796 | Rotate String | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 804 | Unique Morse Code Words | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 806 | Number of Lines To Write String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 812 | Largest Triangle Area | Easy | Math & Logic | Python | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 819 | Most Common Word | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 821 | Shortest Distance to a Character | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 824 | Goat Latin | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 830 | Positions of Large Groups | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 832 | Flipping an Image | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 835 | Image Overlap | Medium | Bit Manipulation | JavaScript | Bitwise Masking & Bit Shift | O(n²) | O(1) | Code | Explanation |
| 836 | Rectangle Overlap | Easy | Math & Logic | JavaScript | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 844 | Backspace String Compare | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 856 | Score of Parentheses | Medium | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 859 | Buddy Strings | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 860 | Lemonade Change | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 867 | Transpose Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 868 | Binary Gap | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 872 | Leaf-Similar Trees | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 876 | Middle of the Linked List | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 877 | Stone Game | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 883 | Projection Area of 3D Shapes | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 884 | Uncommon Words from Two Sentences | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 888 | Fair Candy Swap | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 892 | Surface Area of 3D Shapes | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 896 | Monotonic Array | Easy | Monotonic Stack | Python | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 897 | Increasing Order Search Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 905 | Sort Array By Parity | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 908 | Smallest Range I | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 914 | X of a Kind in a Deck of Cards | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 917 | Reverse Only Letters | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 921 | Minimum Add to Make Parentheses Valid | Medium | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 922 | Sort Array By Parity II | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 925 | Long Pressed Name | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 929 | Unique Email Addresses | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 933 | Number of Recent Calls | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 938 | Range Sum of BST | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 940 | Distinct Subsequences II | Hard | Dynamic Programming | JavaScript | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 941 | Valid Mountain Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 942 | DI String Match | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 944 | Delete Columns to Make Sorted | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 953 | Verifying an Alien Dictionary | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 961 | N-Repeated Element in Size 2N Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 965 | Univalued Binary Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 976 | Largest Perimeter Triangle | Easy | Math & Logic | Python | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 977 | Squares of a Sorted Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 989 | Add to Array-Form of Integer | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 993 | Cousins in Binary Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 997 | Find the Town Judge | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 999 | Available Captures for Rook | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1002 | Find Common Characters | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1005 | Maximize Sum Of Array After K Negations | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1009 | Complement of Base 10 Integer | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1018 | Binary Prefix Divisible By 5 | Easy | Prefix Sum | Python | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1021 | Remove Outermost Parentheses | Easy | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1022 | Sum of Root To Leaf Binary Numbers | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1025 | Divisor Game | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1030 | Matrix Cells in Distance Order | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1037 | Valid Boomerang | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1045 | Customers Who Bought All Products | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1046 | Last Stone Weight | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1047 | Remove All Adjacent Duplicates In String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1050 | Actors and Directors Who Cooperated At Least Three Times | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1051 | Height Checker | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1068 | Product Sales Analysis I | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1070 | Product Sales Analysis III | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1071 | Greatest Common Divisor of Strings | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1075 | Project Employees I | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1078 | Occurrences After Bigram | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1081 | Smallest Subsequence of Distinct Characters | Medium | Monotonic Stack | C++ | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 1084 | Sales Analysis III | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1089 | Duplicate Zeros | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1096 | Brace Expansion II | Hard | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1103 | Distribute Candies to People | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1108 | Defanging an IP Address | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1111 | Maximum Nesting Depth of Two Valid Parentheses Strings | Medium | Stack & Queue | C++ | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1114 | Print in Order | Easy | Hash Map | Java | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1115 | Print FooBar Alternately | Medium | Hash Map | Java | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1116 | Print Zero Even Odd | Medium | Array / General | Java | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1117 | Building H2O | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1122 | Relative Sort Array | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1128 | Number of Equivalent Domino Pairs | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1137 | N-th Tribonacci Number | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1140 | Stone Game II | Medium | Dynamic Programming | C++ | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1141 | User Activity for the Past 30 Days I | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1148 | Article Views I | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1154 | Day of the Year | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1158 | Market Analysis I | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1160 | Find Words That Can Be Formed by Characters | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1164 | Product Price at a Given Date | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1174 | Immediate Food Delivery II | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1175 | Prime Arrangements | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1179 | Reformat Department Table | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1185 | Day of the Week | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1189 | Maximum Number of Balloons | Easy | Hash Map | Kotlin | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1190 | Reverse Substrings Between Each Pair of Parentheses | Medium | Stack & Queue | C++ | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1193 | Monthly Transactions I | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1195 | Fizz Buzz Multithreaded | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1200 | Minimum Absolute Difference | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1204 | Last Person to Fit in the Bus | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1207 | Unique Number of Occurrences | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1211 | Queries Quality and Percentage | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1217 | Minimum Cost to Move Chips to The Same Position | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1221 | Split a String in Balanced Strings | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1226 | The Dining Philosophers | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1232 | Check If It Is a Straight Line | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1251 | Average Selling Price | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1252 | Cells with Odd Values in a Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1260 | Shift 2D Grid | Easy | Tree & Graph | Racket | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1266 | Minimum Time Visiting All Points | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1275 | Find Winner on a Tic Tac Toe Game | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1280 | Students and Examinations | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1281 | Subtract the Product and Sum of Digits of an Integer | Easy | Math & Logic | Python | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1287 | Element Appearing More Than 25% In Sorted Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1288 | Remove Covered Intervals | Medium | Binary Search | Java | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 1290 | Convert Binary Number in a Linked List to Integer | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 1291 | Sequential Digits | Medium | Prefix Sum | C++ | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1295 | Find Numbers with Even Number of Digits | Easy | Math & Logic | Python | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1299 | Replace Elements with Greatest Element on Right Side | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1301 | Number of Paths with Max Score | Hard | Dynamic Programming | PHP | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1306 | Jump Game III | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1309 | Decrypt String from Alphabet to Integer Mapping | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1313 | Decompress Run-Length Encoded List | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1317 | Convert Integer to the Sum of Two No-Zero Integers | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1321 | Restaurant Growth | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1323 | Maximum 69 Number | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1327 | List the Products Ordered in a Period | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1331 | Rank Transform of an Array | Easy | Binary Search | Kotlin | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 1332 | Remove Palindromic Subsequences | Easy | Dynamic Programming | Python | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1337 | The K Weakest Rows in a Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1340 | Jump Game V | Hard | Dynamic Programming | C++ | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1341 | Movie Rating | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1342 | Number of Steps to Reduce a Number to Zero | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1344 | Angle Between Hands of a Clock | Medium | Math & Logic | Java | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1345 | Jump Game IV | Hard | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1346 | Check If N and Its Double Exist | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1351 | Count Negative Numbers in a Sorted Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1356 | Sort Integers by The Number of 1 Bits | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1358 | Number of Substrings Containing All Three Characters | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1360 | Number of Days Between Two Dates | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1365 | How Many Numbers Are Smaller Than the Current Number | Easy | Prefix Sum | TypeScript | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1370 | Increasing Decreasing String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1374 | Generate a String With Characters That Have Odd Counts | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1378 | Replace Employee ID With The Unique Identifier | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1379 | Find a Corresponding Node of a Binary Tree in a Clone of That Tree | Easy | Binary Search | Python | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 1380 | Lucky Numbers in a Matrix | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1385 | Find the Distance Value Between Two Arrays | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1386 | Cinema Seat Allocation | Medium | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1389 | Create Target Array in the Given Order | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1393 | Capital Gain/Loss | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1394 | Find Lucky Integer in an Array | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1399 | Count Largest Group | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1401 | Circle and Rectangle Overlapping | Medium | Math & Logic | JavaScript | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1403 | Minimum Subsequence in Non-Increasing Order | Easy | Dynamic Programming | Python | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1406 | Stone Game III | Hard | Dynamic Programming | PHP | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1407 | Top Travellers | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1408 | String Matching in an Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1413 | Minimum Value to Get Positive Step by Step Sum | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1417 | Reformat The String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1422 | Maximum Score After Splitting a String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1431 | Kids With the Greatest Number of Candies | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1436 | Destination City | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1437 | Check If All 1's Are at Least Length K Places Away | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1441 | Build an Array With Stack Operations | Medium | Stack & Queue | TypeScript | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1446 | Consecutive Characters | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1450 | Number of Students Doing Homework at a Given Time | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1455 | Check If a Word Occurs As a Prefix of Any Word in a Sentence | Easy | Prefix Sum | Python | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1460 | Make Two Arrays Equal by Reversing Subarrays | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1464 | Maximum Product of Two Elements in an Array | Easy | Binary Search | Scala | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 1470 | Shuffle the Array | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1475 | Final Prices With a Special Discount in a Shop | Easy | Monotonic Stack | TypeScript | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 1477 | Find Two Non-overlapping Sub-arrays Each With Target Sum | Medium | Sliding Window | JavaScript | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 1480 | Running Sum of 1d Array | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1484 | Group Sold Products By The Date | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1486 | XOR Operation in an Array | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1491 | Average Salary Excluding the Minimum and Maximum Salary | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1496 | Path Crossing | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1502 | Can Make Arithmetic Progression From Sequence | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1507 | Reformat Date | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1510 | Stone Game IV | Hard | Dynamic Programming | TypeScript | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1512 | Number of Good Pairs | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1517 | Find Users With Valid E-Mails | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1518 | Water Bottles | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1520 | Maximum Number of Non-Overlapping Substrings | Hard | Heap | JavaScript | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 1523 | Count Odd Numbers in an Interval Range | Easy | Heap | Python | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 1527 | Patients With a Condition | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1528 | Shuffle String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1541 | Minimum Insertions to Balance a Parentheses String | Medium | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1544 | Make The String Great | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1550 | Three Consecutive Odds | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1556 | Thousand Separator | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1563 | Stone Game V | Hard | Prefix Sum | Java | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1566 | Detect Pattern of Length M Repeated K or More Times | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1572 | Matrix Diagonal Sum | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1581 | Customer Who Visited but Did Not Make Any Transactions | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1587 | Bank Account Summary II | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1588 | Sum of All Odd Length Subarrays | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1592 | Rearrange Spaces Between Words | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1598 | Crawler Log Folder | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1603 | Design Parking System | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1608 | Special Array With X Elements Greater Than or Equal X | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1614 | Maximum Nesting Depth of the Parentheses | Easy | Stack & Queue | Java | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1619 | Mean of Array After Removing Some Elements | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1621 | Number of Sets of K Non-Overlapping Line Segments | Medium | Prefix Sum | JavaScript | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1624 | Largest Substring Between Two Equal Characters | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1629 | Slowest Key | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1633 | Percentage of Users Attended a Contest | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1636 | Sort Array by Increasing Frequency | Easy | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1637 | Widest Vertical Area Between Two Points Containing No Points | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1640 | Check Array Formation Through Concatenation | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1646 | Get Maximum in Generated Array | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1652 | Defuse the Bomb | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1656 | Design an Ordered Stream | Easy | Bit Manipulation | C++ | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1658 | Minimum Operations to Reduce X to Zero | Medium | Sliding Window | JavaScript | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 1661 | Average Time of Process per Machine | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1662 | Check If Two String Arrays are Equivalent | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1665 | Minimum Initial Energy to Finish Tasks | Hard | Binary Search | C++ | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 1667 | Fix Names in a Table | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1668 | Maximum Repeating Substring | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1672 | Richest Customer Wealth | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1674 | Minimum Moves to Make Array Complementary | Medium | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1678 | Goal Parser Interpretation | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1682 | Most Visited Sector In A Circular Track | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1683 | Invalid Tweets | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1684 | Count the Number of Consistent Strings | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1688 | Count of Matches in Tournament | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1693 | Daily Leads and Partners | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1694 | Reformat Phone Number | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1700 | Number of Students Unable to Eat Lunch | Easy | Stack & Queue | C++ | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 1704 | Determine if String Halves Are Alike | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1710 | Maximum Units on a Truck | Easy | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1716 | Calculate Money in Leetcode Bank | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1720 | Decode XORed Array | Easy | Bit Manipulation | C++ | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1725 | Number Of Rectangles That Can Form The Largest Square | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1729 | Find Followers Count | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1731 | The Number of Employees Which Report to Each Employee | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1732 | Find the Highest Altitude | Easy | Array / General | Kotlin | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1736 | Latest Time by Replacing Hidden Digits | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1741 | Find Total Time Spent by Each Employee | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1742 | Maximum Number of Balls in a Box | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1748 | Sum of Unique Elements | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1752 | Check if Array Is Sorted and Rotated | Easy | Binary Search | C++ | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 1757 | Recyclable and Low Fat Products | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1758 | Minimum Changes To Make Alternating Binary String | Easy | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1763 | Longest Nice Substring | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1773 | Count Items Matching a Rule | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1779 | Find Nearest Point That Has the Same X or Y Coordinate | Easy | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1784 | Check if Binary String Has at Most One Segment of Ones | Easy | Bit Manipulation | C++ | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1789 | Primary Department for Each Employee | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1790 | Check if One String Swap Can Make Strings Equal | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1791 | Find Center of Star Graph | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1795 | Rearrange Products Table | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1796 | Second Largest Digit in a String | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1800 | Maximum Ascending Subarray Sum | Easy | Two Pointers | C++ | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 1805 | Number of Different Integers in a String | Easy | Bit Manipulation | C++ | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1807 | Evaluate the Bracket Pairs of a String | Medium | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1812 | Determine Color of a Chessboard Square | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1816 | Truncate Sentence | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1822 | Sign of the Product of an Array | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1827 | Minimum Operations to Make the Array Increasing | Easy | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1832 | Check if the Sentence Is Pangram | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1833 | Maximum Ice Cream Bars | Medium | Binary Search | Java | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 1837 | Sum of Digits in Base K | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1840 | Maximum Building Height | Hard | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1844 | Replace All Digits with Characters | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1846 | Maximum Element After Decreasing and Rearranging | Medium | Binary Search | Java | Modified Binary Search | O(log n) | O(1) | Code | Explanation |
| 1848 | Minimum Distance to the Target Element | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1854 | Maximum Population Year | Easy | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1859 | Sorting the Sentence | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1861 | Rotating the Box | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1863 | Sum of All Subset XOR Totals | Easy | Bit Manipulation | C++ | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 1869 | Longer Contiguous Segments of Ones than Zeros | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1871 | Jump Game VII | Medium | Prefix Sum | C++ | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1872 | Stone Game VIII | Hard | Prefix Sum | Java | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1873 | Calculate Special Bonus | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1876 | Substrings of Size Three with Distinct Characters | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1880 | Check if Word Equals Summation of Two Words | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1886 | Determine Whether Matrix Can Be Obtained By Rotation | Easy | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1890 | The Latest Login in 2020 | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1893 | Check if All the Integers in a Range Are Covered | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1897 | Redistribute Characters to Make All Strings Equal | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1903 | Largest Odd Number in String | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1907 | Count Salary Categories | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1909 | Remove One Element to Make the Array Strictly Increasing | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1913 | Maximum Product Difference Between Two Pairs | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1914 | Cyclically Rotating a Grid | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1920 | Build Array from Permutation | Easy | Backtracking | C++ | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 1925 | Count Square Sum Triples | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1927 | Sum Game | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1929 | Concatenation of Array | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1935 | Maximum Number of Words You Can Type | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1941 | Check if All Characters Have Equal Number of Occurrences | Easy | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 1945 | Sum of Digits of String After Convert | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 1952 | Three Divisors | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1957 | Delete Characters to Make Fancy String | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1961 | Check If String Is a Prefix of Array | Easy | Prefix Sum | C++ | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 1965 | Employees With Missing Information | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1967 | Number of Strings That Appear as Substrings in Word | Easy | Tree & Graph | Kotlin | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 1971 | Find if Path Exists in Graph | Easy | Dynamic Programming | JavaScript | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 1974 | Minimum Time to Type Word Using Special Typewriter | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1978 | Employees Whose Manager Left the Company | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 1979 | Find Greatest Common Divisor of Array | Easy | Array / General | Kotlin | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1984 | Minimum Difference Between Highest and Lowest of K Scores | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1991 | Find the Middle Index in Array | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 1995 | Count Special Quadruplets | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2000 | Reverse Prefix of Word | Easy | Prefix Sum | JavaScript | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 2029 | Stone Game IX | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2058 | Find the Minimum and Maximum Number of Nodes Between Critical Points | Medium | Two Pointers | C++ | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2091 | Removing Minimum and Maximum From Array | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2095 | Delete the Middle Node of a Linked List | Medium | Fast & Slow Pointers | Java | Floyd Cycle Detection | O(n) | O(1) | Code | Explanation |
| 2126 | Destroying Asteroids | Medium | Bit Manipulation | Java | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2130 | Maximum Twin Sum of a Linked List | Medium | Fast & Slow Pointers | Java | Floyd Cycle Detection | O(n) | O(1) | Code | Explanation |
| 2144 | Minimum Cost of Buying Candies With Discount | Easy | Sliding Window | Kotlin | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 2161 | Partition Array According to Given Pivot | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2196 | Create Binary Tree From Descriptions | Medium | Binary Search | Java | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 2213 | Longest Substring of One Repeating Character | Hard | Binary Search | Java | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 2265 | Count Nodes Equal to Average of Subtree | Medium | Two Pointers | JavaScript | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2267 | Check if There Is a Valid Parentheses String Path | Hard | Stack & Queue | C++ | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 2267 | Check if There Is a Valid Parentheses String Path | Hard | Stack & Queue | C++ | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 2356 | Number of Unique Subjects Taught by Each Teacher | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 2472 | Maximum Number of Non-overlapping Palindrome Substrings | Hard | Two Pointers | JavaScript | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2492 | Minimum Score of a Path Between Two Cities | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2540 | Minimum Common Value | Easy | Sliding Window | C++ | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 2553 | Separate the Digits in an Array | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 2574 | Left and Right Sum Differences | Easy | Prefix Sum | Kotlin | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 2618 | Check if Object Instance of Class | Medium | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2619 | Array Prototype Last | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2620 | Counter | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2621 | Sleep | Easy | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2622 | Cache With Time Limit | Medium | Hash Map | JavaScript | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2623 | Memoize | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2624 | Snail Traversal | Medium | Tree & Graph | TypeScript | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2625 | Flatten Deeply Nested Array | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2626 | Array Reduce Transformation | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2627 | Debounce | Medium | Sliding Window | TypeScript | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 2629 | Function Composition | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2630 | Memoize II | Hard | Hash Map | TypeScript | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2631 | Group By | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2634 | Filter Elements from Array | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2635 | Apply Transform Over Each Element in Array | Easy | Hash Map | TypeScript | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2637 | Promise Time Limit | Medium | Math & Logic | TypeScript | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 2648 | Generate Fibonacci Sequence | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2649 | Nested Array Generator | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2650 | Design Cancellable Function | Hard | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2657 | Find the Prefix Common Array of Two Arrays | Medium | Prefix Sum | C++ | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 2665 | Counter II | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2666 | Allow One Function Call | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2667 | Create Hello World Function | Easy | Tree & Graph | TypeScript | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2677 | Chunk Array | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2685 | Count the Number of Complete Components | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2693 | Call Function with Custom Context | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2694 | Event Emitter | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2695 | Array Wrapper | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2703 | Return Length of Arguments Passed | Easy | Hash Map | TypeScript | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2704 | To Be Or Not To Be | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2705 | Compact Object | Medium | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2721 | Execute Asynchronous Functions in Parallel | Medium | Two Pointers | TypeScript | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2722 | Join Two Arrays by ID | Medium | Hash Map | TypeScript | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2723 | Add Two Promises | Easy | Bit Manipulation | TypeScript | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2724 | Sort By | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2725 | Interval Cancellation | Easy | Heap | TypeScript | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 2726 | Calculator with Method Chaining | Easy | Hash Map | TypeScript | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2727 | Is Object Empty | Easy | Array / General | TypeScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2770 | Maximum Number of Jumps to Reach the Last Index | Medium | Dynamic Programming | C++ | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 2784 | Check if Array is Good | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2812 | Find the Safest Path in a Grid | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2877 | Create a DataFrame from List | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2878 | Get the Size of a DataFrame | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2879 | Display the First Three Rows | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2880 | Select Data | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2881 | Create a New Column | Easy | Two Pointers | Python | Two Pointer Convergence & Scanning | O(n) | O(1) | Code | Explanation |
| 2882 | Drop Duplicate Rows | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2883 | Drop Missing Data | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2884 | Modify Columns | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2885 | Rename Columns | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2886 | Change Data Type | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2887 | Fill Missing Data | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2888 | Reshape Data: Concatenate | Easy | Stack & Queue | Python | Stack Push / Pop Parsing | O(n) | O(n) | Code | Explanation |
| 2889 | Reshape Data: Pivot | Easy | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 2890 | Reshape Data: Melt | Easy | Bit Manipulation | Python | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 2891 | Method Chaining | Easy | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2904 | Shortest and Lexicographically Smallest Beautiful String | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 2948 | Make Lexicographically Smallest Array by Swapping Elements | Medium | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2958 | Length of Longest Subarray With at Most K Frequency | Medium | Hash Map | C++ | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 2996 | Smallest Missing Integer Greater Than Sequential Prefix Sum | Easy | Prefix Sum | Rust | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 3014 | Minimum Number of Pushes to Type Word I | Easy | Hash Map | Dart | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 3016 | Minimum Number of Pushes to Type Word II | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3020 | Find the Maximum Number of Elements in Subset | Medium | Array / General | Java | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3043 | Find the Length of the Longest Common Prefix | Medium | Prefix Sum | C++ | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 3069 | Distribute Elements Into Two Arrays I | Easy | Hash Map | Go | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 3090 | Maximum Length Substring With Two Occurrences | Easy | Array / General | Swift | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3093 | Longest Common Suffix Queries | Hard | Hash Map | Python | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 3116 | Kth Smallest Amount With Single Denomination Combination | Hard | Backtracking | Java | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 3120 | Count the Number of Special Characters I | Easy | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3161 | Block Placement Queries | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3220 | Odd and Even Transactions | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3286 | Find a Safe Walk Through a Grid | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3300 | Minimum Element After Replacement With Digit Sum | Easy | Math & Logic | C++ | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 3302 | Find the Lexicographically Smallest Valid Sequence | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3310 | Remove Methods From Project | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3312 | Sorted GCD Pair Queries | Hard | Dynamic Programming | PHP | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 3336 | Find the Number of Subsequences With Equal GCD | Hard | Dynamic Programming | PHP | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 3345 | Smallest Divisible Digit Product I | Easy | Tree & Graph | Ruby | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3348 | Smallest Divisible Digit Product II | Hard | Math & Logic | Python, TypeScript | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 3414 | Maximum Score of Non-overlapping Intervals | Hard | Heap | JavaScript | Min/Max Heap Priority Selection | O(n) | O(n) | Code | Explanation |
| 3421 | Find Students Who Improved | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3436 | Find Valid Emails | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3451 | Find Invalid IP Addresses | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3465 | Find Products with Valid Serial Numbers | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3471 | Find the Largest Almost Missing Integer | Easy | Prefix Sum | Kotlin | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 3475 | DNA Pattern Recognition | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3482 | Analyze Organization Hierarchy | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3483 | Unique 3-Digit Even Numbers | Easy | Math & Logic | JavaScript | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 3497 | Analyze Subscription Conversion | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3498 | Reverse Degree of a String | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3499 | Maximize Active Section with Trade I | Medium | Monotonic Stack | C++ | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 3501 | Maximize Active Section with Trade II | Hard | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3513 | Number of Unique XOR Triplets I | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3514 | Number of Unique XOR Triplets II | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3517 | Smallest Palindromic Rearrangement I | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3518 | Smallest Palindromic Rearrangement II | Hard | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3521 | Find Product Recommendation Pairs | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3524 | Find X Value of Array I | Medium | Binary Search | JavaScript | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 3525 | Find X Value of Array II | Hard | Binary Search | JavaScript | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 3532 | Path Existence Queries in a Graph I | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3534 | Path Existence Queries in a Graph II | Hard | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3536 | Maximum Product of Two Digits | Easy | Math & Logic | Erlang | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 3550 | Smallest Index With Digit Sum Equal to Index | Easy | Prefix Sum | JavaScript | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 3554 | Find Category Recommendation Pairs | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3558 | Number of Ways to Assign Edge Weights I | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3559 | Number of Ways to Assign Edge Weights II | Hard | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3564 | Seasonal Sales Analysis | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3568 | Minimum Moves to Clean the Classroom | Medium | Sliding Window | C++ | Dynamic Sliding Window Traversal | O(n) | O(1) | Code | Explanation |
| 3570 | Find Books with No Available Copies | Easy | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3580 | Find Consistently Improving Employees | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3586 | Find COVID Recovery Patients | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3601 | Find Drivers with Improved Fuel Efficiency | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3611 | Find Overbooked Employees | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3612 | Process String with Special Operations I | Medium | Tree & Graph | Java | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3614 | Process String with Special Operations II | Hard | Tree & Graph | Python | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3617 | Find Students with Study Spiral Pattern | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3620 | Network Recovery Pathways | Hard | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3622 | Check Divisibility by Digit Sum and Product | Easy | Math & Logic | C | Mathematical Simulation & Modular Arithmetic | O(n) | O(1) | Code | Explanation |
| 3626 | Find Stores with Inventory Imbalance | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3629 | Minimum Jumps to Reach End via Prime Teleportation | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3633 | Earliest Finish Time for Land and Water Rides I | Easy | Array / General | Kotlin | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3635 | Earliest Finish Time for Land and Water Rides II | Medium | Array / General | Java | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3642 | Find Books with Polarized Opinions | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3657 | Find Loyal Customers | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3658 | GCD of Odd and Even Sums | Easy | Array / General | Kotlin | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3660 | Jump Game IX | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3673 | Find Zombie Sessions | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3689 | Maximum Total Subarray Value I | Medium | Binary Search | Java | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 3691 | Maximum Total Subarray Value II | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3699 | Number of ZigZag Arrays I | Hard | Hash Map | PHP | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 3700 | Number of ZigZag Arrays II | Hard | Tree & Graph | PHP | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3702 | Longest Subsequence With Non-Zero Bitwise XOR | Medium | Dynamic Programming | C++ | Memoization & State Transition | O(n) | O(n) | Code | Explanation |
| 3705 | Find Golden Hour Customers | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3716 | Find Churn Risk Customers | Medium | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3718 | Smallest Missing Multiple of K | Easy | Prefix Sum | C# | Prefix Sum Precomputation | O(n) | O(n) | Code | Explanation |
| 3720 | Lexicographically Smallest Permutation Greater Than Target | Medium | Backtracking | C++ | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 3731 | Find Missing Elements | Easy | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3734 | Lexicographically Smallest Palindromic Permutation Greater Than Target | Hard | Backtracking | Java | Backtracking Recursive Search | O(n) | O(1) | Code | Explanation |
| 3737 | Count Subarrays With Majority Element I | Medium | Monotonic Stack | Java | Monotonic Stack Filtering | O(n) | O(n) | Code | Explanation |
| 3739 | Count Subarrays With Majority Element II | Hard | Array / General | PHP | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3742 | Maximum Path Score in a Grid | Medium | Tree & Graph | C++ | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3751 | Total Waviness of Numbers in Range I | Medium | Array / General | Java | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3753 | Total Waviness of Numbers in Range II | Hard | Array / General | Python | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3754 | Concatenate Non-Zero Digits and Multiply by Sum I | Easy | Bit Manipulation | Kotlin | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 3756 | Concatenate Non-Zero Digits and Multiply by Sum II | Medium | Bit Manipulation | Java | Bitwise Masking & Bit Shift | O(n) | O(1) | Code | Explanation |
| 3764 | Most Common Course Pairs | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3793 | Find Users with High Token Usage | Easy | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3808 | Find Emotionally Consistent Users | Medium | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3832 | Find Users with Persistent Behavior Patterns | Hard | Database / SQL | SQL | SQL Query / Relational Join & Window Function | O(n) | O(n) | Code | Explanation |
| 3838 | Weighted Word Mapping | Easy | Hash Map | Kotlin | Complement Lookup / Hash Table Frequency | O(n) | O(n) | Code | Explanation |
| 3867 | Sum of GCD of Formed Pairs | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3870 | Count Commas in Range | Easy | Tree & Graph | JavaScript | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3871 | Count Commas in Range II | Medium | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3875 | Construct Uniform Parity Array I | Easy | Binary Search | C++ | Modified Binary Search | O(n) | O(1) | Code | Explanation |
| 3876 | Construct Uniform Parity Array II | Medium | Array / General | C++ | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |
| 3903 | Smallest Stable Index I | Easy | Tree & Graph | JavaScript | Depth-First Search (DFS) / Breadth-First Search (BFS) | O(n) | O(n) | Code | Explanation |
| 3904 | Smallest Stable Index II | Medium | Array / General | JavaScript | In-Place Array Traversal & Index Mapping | O(n) | O(1) | Code | Explanation |