结构体输出今天是今年的第几天？

#include <iostream>using namespace std;struct Date{int year;int month;int day;};int main(){Date date;cout<<"input year,month,day:";cin>>date.year>>date.month>>date.day;int days;    switch(date.month){case 1:days=date.day;break;case 2:days=date.day+31;break;case 3:days=date.day+59;break;    case 4:days=date.day+90;break;case 5:days=date.day+120;break;case 6:days=date.day+151;break;case 7:days=date.day+181;break;case 8:days=date.day+212;break;case 9:days=date.day+243;break;case 10:days=date.day+273;break;case 11:days=date.day+304;break;case 12:days=date.day+334;break;}if(date.year%4==0 && date.year/100==0 || date.year%400==0)date.day+=1;cout<<date.month<<"月"<<date.day<<"日是"<<date.year<<"年的第"<<days<<"天."<<endl;return 0;}