test.c

#include "stdio.h"
 
bool leap_year(int y) {  
    int is_leap;
    is_leap = (y % 400 == 0) || 
        ((y % 4 == 0) && !(y % 100 == 0));
    return is_leap;
} 
    
int main(void) {
    if (leap_year(2016)) {
        printf("2016 is leap year");
    }
    else {
        printf("2016 is not leap year");
    }
    return 0;
}