acm 10812: Beat the Spread!

[[心得]  0.004

#include <stdio.h>

int main()
{
  int a,b,data;

  while(scanf("%d",&data)==1)
  {
       int k;                          
       for(k=0;k<data;k++)
       {
           int x,y;      
           scanf("%d %d",&a,&b);
           if(b>a||(a+b)%2!=0)
              printf("impossible\n");  
           else
           {
              x = (a+b)/2;
              y = a-x;
              if(x<0||y<0)
                 printf("impossible\n"); 
              else
                 printf("%d %d\n",x,y);                             
           }  
       }                 
  }
   
   
  system("pause");
  return 0;   
}