题意:
input a b
输入的是两个数的和和差,其中a为和,b为差,如果a
#include <iostream>
using namespace std;
int main()
{
int N;
cin>>N;
while(N--){
int a,b;
cin>>a>>b;
if(a<b | (a-b)%2!=0) cout<<"impossible"<<endl;
else{
cout<<(a+b)/2<<" "<<(a-b)/2<<endl;
}
}
}