将判断闰年的功能定义为子函数，通过调用该函数判断输入范围内哪些是闰年，输出并统计闰年的总数
#include <stdio.h>
#include <math.h>
int runnian (int year)
{
int flag = 0;
if( ( year % 4 == 0 && year % 100 !=0 ) || year % 400 == 0)
{
printf("%5d", year);
flag = 1;
}
return flag;
}
int main ()
{
int min , max , i , n = 0;
printf("请输入年份范围：\n");
scanf("%d%d", &min , &max);
printf("%d到%d之间闰年有：\n", min , max);
for( i = min; i <= max; i++)
{
if(runnian(i) == 1)
{
if(++n % 5 == 0)
printf("\n");
}
}
printf("\n%d到%d年之有%d个闰年。\n", min , max , n);
}
