001：判断闰年

 1 #include <stdio.h>
 2 
 3 int main( int argc, char* argv[] )
 4 {
 5     
 6     unsigned long year;
 7 
 8     printf("Input a year:");
 9     scanf("%lu", &year);
10     if((year % 4 == 0 && year % 100 != 0)||(year % 400 == 0))
11     {
12         printf("Year %lu is a leap year.\n", year);
13     }
14     else
15     {
16         printf("Year %lu is not a leap year.\n", year);
17     }
18     return 0;
19 }