DayOfYear.java

package LeetcodePractice;

public class DayOfYear {
    public static int dayOfYear(String date) {
        String[] parts = date.split("-");
        int year = Integer.parseInt(parts[0]);
        int month = Integer.parseInt(parts[1]);
        int day = Integer.parseInt(parts[2]);

        int[] daysInMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

        
        if (isLeapYear(year)) {
            daysInMonth[1] = 29;
        }

        int dayOfYear = day;
        for (int i = 0; i < month - 1; i++) {
            dayOfYear += daysInMonth[i];
        }

        return dayOfYear;
    }

    private static boolean isLeapYear(int year) {
        return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
    }

    public static void main(String[] args) {
        System.out.println(dayOfYear("2019-01-09"));
        System.out.println(dayOfYear("2019-02-10")); 
        System.out.println(dayOfYear("2020-03-01"));
}
}