ch23-15.c

C语言程序设计上机指导与练习 冶金工业出版社 刘怀亮

#include<stdio.h> 
#include<conio.h> 
struct ymd 
{ 
   int day; 
   int month; 
   int year; 
}; 
int dayof[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}; 
int days(struct ymd *p) 
{ 
   int i,d; 
   if(p->year%4==0&&p->year%100!=0||p->year%400==0) 
   dayof[2]=29; 
   d=p->day; 
   for(i=1;i<p->month;i++) 
      d=d+dayof[i]; 
   return (d); 
} 

void main() 
{ 
   struct ymd date; 
   int d; 
   clrscr(); 
   for (;;) 
   { 
      printf("\n-----------------------------------\n\n"); 
      printf("date(yyyy/mm/dd)=? (yyyy=0--Exit)\n\n"); 
      scanf("%d/%d/%d",&date.year,&date.month,&date.day); 
      if(date.year==0) 
         break; 
      d=days(&date); 
      printf("\nThe day of the year is %d !\n\n",d); 
   } 
}