Is_Leap_Year

[Khusro-S]

Leap Year Problem

This problem involves determining whether a given year is a leap year based on the rules defined in the Gregorian calendar. In a leap year, an extra day (February 29) is added to the calendar to account for the fact that a year is not exactly 365 days, but approximately 365.25 days. The task is to implement a function is_leap(year) that takes an integer year as input and returns True if the year is a leap year and False otherwise.

Key Considerations:

Leap Year Rules:

1. If the year is divisible by 4, it's usually a leap year.
2. However, if the year is also divisible by 100, it is not a leap year, unless:
3. The year is divisible by 400. If it is, then it is a leap year.
   In short, If the year is divisible by 4, but not divisible by 100, or if it is divisible by 400, then it is a leap year.

This logic means:

• Years like 2000 and 2400 are leap years because they are divisible by 400.
• Years like 1800, 1900, 2100, 2200, 2300, and 2500 are not leap years because they are divisible by 100 but not by 400.
• Years like 1996, 2004, and 2008 are leap years because they are divisible by 4 but not by 100.

Constraints:

• The input year is a positive integer representing a year in the Gregorian calendar.
• The year can be any valid integer that represents a calendar year, including edge cases like very old years or very large years.
• The function must efficiently handle the input year and output the correct Boolean value.

Sample Test Cases:

Test Case 1:

• Input: 1990
• Output: False
• Explanation: 1990 is not divisible by 4, hence it is not a leap year.

Test Case 2:

• Input: 2000
• Output: True
• Explanation: 2000 is divisible by 400, so it is a leap year.

Test Case 3:

• Input: 2100
• Output: False
• Explanation: 2100 is divisible by 100 but not by 400, so it is not a leap year.

Test Case 4:

• Input: 2004
• Output: True
• Explanation: 2004 is divisible by 4 but not by 100, so it is a leap year.