下面来介绍一下如何通过C编程来实现输入年月日算天数的求解，具体如下：
问题描述：当输入年月日后，即可推断该日期是这一年的第几天。
#include <stdio.h>struct{int year;int month;int day;}date;int main(){int i,days;int day_tab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};printf("input year,month,day:");scanf("%d,%d,%d",&date. year,&date.month,&date.day);days=0;for(i=1;i<date.month;i++)days=days+day_tab[i];days=days+date.day;if((date.year%4==0 && date.year%100!=0 || date.year%400==0) && date.month>=3)days=days+1;printf("%d/%d is the %dth day in %d.\n",date.month,date.day,days,date.year);return 0;}
