闰年可以被 4 整除，世纪年除外(以 00 结尾的年份)。只有能被 400 整除的世纪年才是闰年。
例如
1999 年不是闰年
2000 年是闰年
2004 年是闰年
检查闰年的程序
#include <stdio.h> int main() { int year; printf("Enter a year: "); scanf("%d", &year); // leap year if perfectly divisible by 400 if (year % 400 == 0) { printf("%d is a leap year.", year); } // not a leap year if divisible by 100 // but not divisible by 400 else if (year % 100 == 0) { printf("%d is not a leap year.", year); } // leap year if not divisible by 100 // but divisible by 4 else if (year % 4 == 0) { printf("%d is a leap year.", year); } // all other years are not leap years else { printf("%d is not a leap year.", year); } return 0; }
输出 1
Enter a year: 1900 1900 is not a leap year.
输出 2
Enter a year: 2012 2012 is a leap year.
