PlusOne.java

package LeetcodePractice;
import java.util.Arrays;

public class PlusOne {

    public static int[] plusOne(int[] digits) {
        int n = digits.length;
        
        
        for (int i = n - 1; i >= 0; i--) {
            if (digits[i] < 9) {
                digits[i]++; 
                return digits;
            }
            digits[i] = 0; 
        }
       
        int[] result = new int[n + 1];
        result[0] = 1;
        return result;
    }

    
    public static void main(String[] args) {
        

        int[] digits1 = {1, 2, 3};
        System.out.println(Arrays.toString(plusOne(digits1)));

        int[] digits2 = {4, 3, 2, 1};
        System.out.println(Arrays.toString(plusOne(digits2)));

        int[] digits3 = {9};
        System.out.println(Arrays.toString(plusOne(digits3)));
    }
    
}