fjnu2016-2017 低程 PROBLEM B 捧杯

#include <iostream>
#include <cmath>
using namespace std;

int _gcd(int x,int y){
return y==0?x:_gcd(y,x%y);
}

void main()
{
int T,x0,y0,n;
cin>>T;
while(T--)
{
cin>>x0>>y0;
cin>>n;
int x1=0,y1=0;
for(int i=0;i<n;i++)
{
int x2,y2;
cin>>x2>>y2;
x1+=x2;
y1+=y2;
}
x1-=x0*n;
y1-=y0*n;

if(x1==0&&y1==0)
cout<<0<<' '<<0<<endl;
else if(x1==0&&y1!=0)
cout<<0<<' '<<y1<<endl;
else if(x1!=0&&y1==0)
cout<<x1<<' '<<0<<endl;
else if(x1!=0&&y1!=0)
{
int gcd=_gcd(abs(x1),abs(y1));
cout<<x1/gcd<<' '<<y1/gcd<<endl;
}
}
}