程序代码：

#include <stdio.h>
void main()
{
    int year,leap;
    scanf("%d",&year);
    if (year%4! =0)
        leap=0;
    else if (year%100! =0)
        leap=1;
    else if (year%400! =0)
        leap=0;
    else
    leap=1;
    if (leap)
        printf("%d is",year);
    else
        printf("%d is not",year);
    printf("a leap year.\n");
}