例4.8 写一段程序，判断某一年是否为闰年

#include<stdio.h>
int main() {
  int year;
  printf("please input year:");
  scanf("%d", &year);
  if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
    printf("%d is run year\n", year);
  }
  else {
    printf("%d isn't run year\n", year);
  }
  return 0;
}