#include<iostream>
#include<vector>
#include<string>
#include<type_traits>
#include<sstream>
#include<tuple>
#include<bitset>
#include<regex>
#include<set>
#include<queue>
#include<map>
using namespace std;
bool compare(pair<int,int> a,pair<int,int> b){
if (a.first == b.first) return a.second < b.second;
return a.first < b.first;
}
int main(){
int T;
cin >> T;
int N;
while (T--){
cin >> N;
vector<pair<int, int>> point;
set<pair<int, int>> search;
double ave_x=0;
for (int i = 0; i < N; i++){
pair<int, int> temp;
cin >> temp.first >> temp.second;
ave_x += temp.first;
point.push_back(temp);
search.insert(temp);
}
sort(point.begin(),point.end(),compare);
ave_x /= N;
bool flag = true;
for (int i = 0; i < N; i++){
pair<int, int> temp = point[i];
pair<int, int> temp1;
temp1.second = temp.second;
temp1.first = 2 * ave_x - temp.first;
if (search.find(temp1) == search.end()){
cout << "NO" << endl;
flag = false;
break;
}
}
if (flag) cout << "YES" << endl;
}
//system("pause");
return 0;
}
1595 - Symmetry
最新推荐文章于 2021-04-12 19:04:07 发布