对当前时间加一天

#include<iostream.h>
class CDate{
private:
	int a,b,c,flag;
public:
	void out(void)
	{
		cout<<"please input year,month,day by order"<<endl;		

	}
	void output()
	{
        cout<<"after plus the date what you input ,the final is"<<a<<"year"<<b<<"month"<<c+1<<"day"<<endl;
	}
	void center()
	{
		CDate CDate1;
		cin>>a>>b>>c;                  
		switch(b)
		{
          case 1:
	      case 3:
	      case 5:
	      case 7:
	      case 8:
	      case 10:
             if(c>=31)
			 { 
				c=c%31;
			   b=b+1;
			   
			 }
			 else c=c;
	      case 12:
			  if(c>=31)
			  { 
				c=c%31;
				b=1;
				a=a+1;
			  }
		    
		    else c=c;break;
	      case 4:
	      case 6:
	      case 9:
	      case 11:
		     if(c>30)
		        c=(c%30);break;
	      case 2:
		     if(!(a%400))
			    flag=1;
		     else if(!(a%4)&&a%100)
			        flag=1;
			      else 
					  flag=0;
             if(flag)
			 {
		      if(c>=29)
			  {
				  c=c%29;
			     
			  }
		      else
			  {  
				  c=c;
		          
			  }
			 }
		   
           else 
		   {
			 if(c>=28)
			 {c=c%28;
				 b=b+1;
				  
			 }
			 else
				 c=c;
               
		   } 

		}
	}

     
};
void main()
{
   
    CDate CDate1;
	CDate1.out();
	CDate1.center();
	CDate1.output();
	
    
}
#include<iostream.h>
class CDate{
private:
	int