第几天

数组：

#include<stdio.h>
int main()
{
int num[12]={31,28,31,30,31,30,31,31,30,31,30,31};
int year,month,day;


while(scanf("%d/%d/%d",&year,&month,&day)!=EOF){
int sum=0,i;

num[1]=((year%4==0&&year%100!=0)||year%400==0)?29:28;

for(i=0;i<month-1;i++){
sum+=num[i];
}

sum+=day;


printf("%d\n",sum);
}
return 0;
}

Switch:

 #include<stdio.h>
int main()
{
int y,m,d,sum;
scanf("%d%d%d",&y,&m,&d);
switch(m)
{
case 1:sum=0;break;
case 2:sum=31;break;
case 3:sum=31+28;break;
case 4:sum=90;break;
case 5:sum=120;break;
case 6:sum=151;break;
case 7:sum=181;break;
case 8:sum=212;break;
case 9:sum=243;break;
case 10:sum=273;break;
case 11:sum=304;break;
case 12:sum=334;break;
}
sum+=d;

if(y%400==0||y%4==0&&y%100!=0&&m>2)
sum++;

printf("%d年%d月%d天是第%d天\n",y,m,d,sum);



return 0;