C Program To Check Leap Year

A year is a leap year if the following conditions are satisfied: 

1. The year is multiple of 400.
2. The year is multiple of 4 and not multiple of 100.

Following is pseudo-code 

if year is divisible by 400 then is_leap_year
else if year is divisible by 100 then not_leap_year
else if year is divisible by 4 then is_leap_year
else not_leap_year

C

// C program to check if a given
// year is leap year or not
#include <stdio.h>
#include <stdbool.h>

bool checkYear(int year)
{
    // If a year is multiple of 400,
    // then it is a leap year
    if (year % 400 == 0)
        return true;

    // Else If a year is multiple of 100,
    // then it is not a leap year
    if (year % 100 == 0)
        return false;

    // Else If a year is multiple of 4,
    // then it is a leap year
    if (year % 4 == 0)
        return true;
    return false;
}

// Driver code
int main()
{
    int year = 2000;

    checkYear(year)? printf("Leap Year"):
                     printf("Not a Leap Year");
    return 0;
}

Output:

Leap Year

Time Complexity: O(1)

Auxiliary Space: O(1)

How to write the above code in one line?

C

// One line C program to check if a
// given year is leap year or not
#include <stdio.h>
#include <stdbool.h>

bool checkYear(int year)
{
// Return true if year is a multiple
// of 4 and not multiple of 100.
// OR year is multiple of 400.
return (((year % 4 == 0) &&
        (year % 100 != 0)) ||
        (year % 400 == 0));
}

// Driver code
int main()
{
    int year = 2000;

    checkYear(year)? printf("Leap Year"):
                     printf("Not a Leap Year");
    return 0;
}

Output:

Leap Year

Time Complexity: O(1)

Auxiliary Space: O(1)

Please refer complete article on Program to check if a given year is leap year for more details!