各位大大幫忙看看吧ORZ

#include<iostream>  
using namespace std;  
int main()  
{  
    int a,m,r,s;  
    while(cin>>a)
    {
         int x[a],y[a];
         for(int k=0;k<a;k++)
         cin>>x[k]>>y[k];
         for(int k=0;k<a;k++)
            {
            m=0;
            r=x[k];
            s=y[k];
            if(r%2==1 && s%2==1)
            m=(r+s)*((s-r)/2+1)/2;
            else if(r%2==0 && s%2==1)
            m=(r+s+1)*((s-r-1)/2+1)/2;
            else if(r%2==1 && s%2==0)
            m=(r+s-1)*((s-1-r)/2+1)/2;
            else
            m=(r+s)*((s-2-r)/2+1)/2;
            cout<<"Case "<<k+1<<": "<<m<<endl;
            }     
    }
           

return 0 ;  
} 

感謝^^

AC了