#includestdio.h struct date {int y,m,d;}; int fun(struct date *p) {int a=0; switch(p-m) {case 12:a+=30; case 11:a+=31; case 10:a+=30; case 9:a+=31; case 8:a+=31; case 7:a+=30; case 6:a+=31; case 5:a+=30; case 4:a+=31; case 3:if(p-y%4==0&&p-y%100!=0||p-y%400==0) a+=29;else a+=28; case 2:a+=31; case 1:a+=p-d; } return a; } void main() {struct date d,*pd; int i,a,b; pd=&d; printf(以yy.mm.dd的格式输入一个日期\n); scanf(%4d%c%2d%c%2d,&pd-y,&a,&pd-m,&b,&pd-d); i=fun(pd); printf(是该年的第%d天\n,i); }