第十八周项目四-1 定义结构体算当年第几天

/*
*ALL rights reserved.
*文件名称:shibazhouxiangmu（1）
*作者：李长鸿
*完成时间：2014.12.23
*问题描述：当年第几天
*/
#include <iostream>
#include<string>
using namespace std;
struct Date
{
int year;
int mouth;
int day;
} date;
int main()
{
cout<<"input year,mouth,day:"<<endl;
cin>>date.year>>date.mouth>>date.day;
while(date.mouth>12||date.mouth<0||date.day>31||date.day<0||(date.mouth==2&&date.day>29))
{
cout<<"输入有误，请再次输入正确的日期："<<endl;
cin>>date.year>>date.mouth>>date.day;
}
int days=0,i,a[13]= {0,31,28,31,30,31,30,31,31,30,31,30,31};
for(i=1; i<date.mouth; i++)
days=days+a[i];
days=days+date.day;
if((date.year%4==0&&date.year%100!=0)||(date.year%400==0)&&date.mouth>2)
days=days+1;
cout<<date.year<<"年"<<date.mouth<<"月"<<date.day<<"日是"<<date.year<<"年的第"<<days<<"天"<<endl;
return 0;
}