题解 | #计算日期到天数转换#

#include <iostream>
using namespace std;
int main()
{
    int year,mon,day;
    while(cin>>year>>mon>>day)
    {
        int sum=0;
        if(mon==1)
        {
            cout<<day<<endl;
        }
        else 
        {
             sum=(mon-1)*30;
            if(mon==2)
             cout<<sum+1+day<<endl;
            if(mon==3)
            {
                if(year%4==0)
                    cout<<sum-1+day<<endl;
                else 
                    cout<<sum-1+day<<endl;
            }
             if(mon==4||mon==5)
            {
                if(year%4==0)
                    cout<<sum+1+day<<endl;
                else 
                    cout<<sum+day<<endl;
            }
             if(mon==6||mon==7)
            {
                if(year%4==0)
                    cout<<sum+2+day<<endl;
                else 
                    cout<<sum+1+day<<endl;
            }
             if(mon==8)
            {
                if(year%4==0)
                    cout<<sum+3+day<<endl;
                else 
                    cout<<sum+2+day<<endl;
            }
            if(mon==9||mon==10)
            {
                if(year%4==0)
                    cout<<sum+4+day<<endl;
                else 
                    cout<<sum+3+day<<endl;
            }
            if(mon==11||mon==12)
            {
                if(year%4==0)
                    cout<<sum+5+day<<endl;
                else 
                    cout<<sum+4+day<<endl;
            }
        }       
    }
    return 0;
}