输入年,月,打印出该年的天数：
#include<stdio.h>
main()
{
int y,m,d;
printf("year month=");scanf("%d%d",&y,&m);
switch(m){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:d=31;break;
case 4:
case 6:
case 9:
case 11:d=30;break;
case 2:if (y%4==0 && y%100!=0 || y%400==0) d=29; else d=28;
}
printf("days=%d\n",d);
}
扩展资料：
输入某年某月（包括闰年），编程输出该年的该月拥有的天数：
#include<stdio.h>
#define MONTHS 12
int main(){
int days[2][MONTHS]={{31,28,31,30,31,30,31,31,30,31,30,31},
{31,29,31,30,31,30,31,31,30,31,30,31}};
int year,month;
do{
printf("Input year,month:");
scanf("%d,%d",&year,&month);
}while(month<1||month>12);
if(((year%4==0)&&(year%100 !=0))||(year%400==0))
printf("The number of days is %d\n",days[1][month-1]);
else
printf("The number of days is %d\n",days[0][month-1]);
return 0;
}
参考资料来源：百度百科—include
#include "stdio.h"
void main(void){
int year,days=0;
printf("Please enter the year number...\nyear=");
scanf("%d",&year);
if(year%4==0 && year%100!=0 || year%400==0) days++;
printf("There are %d days in %d.\n",365+days,year);
}
