/*****
                              leapyear()

      This function determines whether a given year is a leap year.

   Argument list:    int year       the year

   Return value:     int            1 if it is a leap year, 0 if not

*****/

int leapyear(int year)
{
   if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
      return 1;
   else
      return 0;
}