#include <stdio.h>
int main()
{
int year;
printf("Enter a year: ");
scanf("%d",&year);
if(year%4 == 0)
{
if( year%100 == 0)
{
// year is divisible by 400, hence the year is a leap year
if ( year%400 == 0)
printf("%d is a leap year.", year);
else
printf("%d is not a leap year.", year);
}
else
printf("%d is a leap year.", year );
}
else
printf("%d is not a leap year.", year);
return 0;
}

Hints: Follow the steps:
1. if the year is evenly divisible by 4 then it is a leap year, otherwise go to step 2.
2. if the year is evenly divisible by 100 then go to step 3, otherwise it is a leap year.
3. if the year is evenly divisible by 400 then it is leap year, otherwise it is not a leap year.
In simple words we can say, if (year is divisible by 4 AND year is not divisible by 100) OR (year is
divisible by 400) then it is a leap year, otherwise it is not a leap year.