Symmetry (UVA - 1595)

版权声明：欢迎转载!拒绝抄袭. https://blog.csdn.net/qq_36257146/article/details/87560255

#include <iostream>
#include <bits/stdc++.h>
using namespace std;

struct Node
{
    int x;
    int y;
    Node(int a,int b)
    {
        x = a;y = b;
    }
    bool operator < (const Node &a) const
    {
        if(a.y == y)
            return a.x>x;
        else
            return a.y>y;
    }
};
vector<Node>n1;
vector<Node>n2;



int main()
{
    int c,n;
    int x,y;
    cin>>c;
    while(c--)
    {
        n1.clear();
        n2.clear();
        int sum = 0;
        cin>>n;
        for(int i = 0;i<n;i++)
        {
            cin>>x>>y;
            sum+=x;
            n1.push_back(Node(n*x,y));
            n2.push_back(Node(n*x,y));
        }
        sort(n1.begin(),n1.end());
        for(int i = 0;i<n2.size();i++)
        {
            n2[i].x = 2*sum-n2[i].x;
        }
        sort(n2.begin(),n2.end());
        int flag = 1;
        for(int i = 0;i<n1.size();i++)
        {
            if(n1[i].x!=n2[i].x||n1[i].y!=n2[i].y)
            {
                flag = 0;
                break;
            }
        }
        if(!flag) cout<<"NO"<<endl;
        else cout<<"YES"<<endl;
    }
    return 0;
}
/**
3
5
-2 5
0 0
6 5
4 0
2 3
4
2 3
0 4
4 0
0 0
4
5 14
6 10
5 10
6 14
**/