Problem
A year divisible by 4 is a leap year unless it is also divisible by 100. Years divisible by 400 are leap years despite that exception. Apply this arithmetic rule to every allowed input year.
Implement leap_year(year).
Input
year: The year to check.
Output
Return true for a leap year and false otherwise.
Constraints
1 ≤ year ≤ 9999.
Examples
Input:
year = 2024
Expected output:
expected = TrueInput:
long long year = 2024;
Expected output:
bool expected = true;Input:
long year = 2024;
Expected output:
bool expected = true;Explanation
2024 is divisible by 4 and not by 100.
Input:
year = 2100
Expected output:
expected = FalseInput:
long long year = 2100;
Expected output:
bool expected = false;Input:
long year = 2100;
Expected output:
bool expected = false;Explanation
2100 is divisible by 100 but not by 400, so the century exception applies.
How to approach it
Try on your own first, then open one hint at a time.
Hint 1
Most years follow the divisible-by-4 rule, but centuries are exceptions.
Hint 2
A year divisible by 400 is still a leap year, even though it is also divisible by 100.
Hint 3
Check the exception before rejecting century years, or you may misclassify years like 2000.
Expected complexity
O(1) time, O(1) extra space
References
This challenge is adapted for CodeUtility. Follow the statement and constraints above.