C++练习 | 计算两日期之间天数差

 #include<iostream>
 #include<string>
 #include<cstring>
 using namespace std;

 class Date
 {
 private:
     int year;
     int month;
     int day;
 public:
     void get()
     {
         int a,b,c;
         cin>>a;
         getchar();
         cin>>b;
         getchar();
         cin>>c;
         year=a;
         month=b;
         day=c;
         return;
     }
     friend int days(Date a,Date b);
 };

 int days(Date a,Date b)
 {
     int day1=;
     Date temp;
     if((a.year<b.year)||((a.year==b.year)&&(a.month<b.month))||((a.year==b.year)&&(a.month==b.month)&&(a.day<b.day)))
     {
         temp=a;
         a=b;
         b=temp;//保证a比b日期靠后
     }
     if(a.year!=b.year)
     {
         day1+=(a.year-b.year-)*;//不考虑闰年和不完整年的整年天数
         day1+=((((a.year-)/) - ((a.year-)/) + ((a.year-)/))-(((b.year-)/) - ((b.year-)/) + ((b.year-)/)));//期间闰年天数
     for(int i=b.month;i<=;i++)
     {
         switch(i)
         {
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
         }
     }
     day1-=b.day;
     for(int i=a.month-;i>=;i--)
     {
         switch(i)
         {
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
             case :
             {
                 day1+=;
                 break;
             }
         }
     }
     day1+=a.day;
     if(((b.year%==&&b.year%!=)||(b.year%==))&&(b.month>))
         day1-=;
     if(((a.year%==&&a.year%!=)||(a.year%==))&&(a.month>))
         day1+=;
     }
     else
     {
         for(int i=b.month;i<a.month;i++)
         {
             switch(i)
             {
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
                 case :
                 {
                     day1+=;
                     break;
                 }
             }
         }
         day1+=a.day;
         day1-=b.day;
         if(b.month==&&b.day==)
             day1++;
         if(((a.year%==&&a.year%!=)||(a.year%==))&&(b.month<=&&b.day!=&&a.month>))
         {
             day1++;
         }
     }
     return day1;
 }

 int main()
 {
     Date y1,y2;
     y1.get();
     y2.get();
     cout<<days(y1,y2);
     return ;
 }