Submission #596693

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Source Code Expand

#include <cstdio>
#include <string>
#include <cmath>
#include <cstring>
#include <vector>
#include <map>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 100000 + 10;
const int MOD = (int)1e9 + 7;

int n;
int x[N], y[N];
map<pair<int, int>, int> vec;

void solve()
{
	cin >> n;
	for(int i = 0; i < n; ++ i) {
		cin >> x[i] >> y[i];
		vec[make_pair(x[i], y[i])] = i;
	}
	for(int i = 0; i < n; ++ i) {
		for(int j = i + 1; j < n; ++ j) {
			int vy = x[i] - x[j];
			int vx = y[j] - y[i];
			for(int k = 0; k < 2; ++ k) {
				if (vec.count(make_pair(x[i] + vx, y[i] + vy)) && vec.count(make_pair(x[j] + vx, y[j] + vy))) {
					cout << 4 << endl;
					vector<int> ids;
					ids.push_back(i + 1);
					ids.push_back(j + 1);
					ids.push_back(vec[make_pair(x[i] + vx, y[i] + vy)] + 1);
					ids.push_back(vec[make_pair(x[j] + vx, y[j] + vy)] + 1);
					sort(ids.begin(), ids.end());
					for(int w = 0; w < 4; ++ w) {
						cout << ids[w] << endl;
					}
					return;
				}
				vx = -vx;
				vy = -vy;
			}
		}
	}
	cout << 0 << endl;
}

int main()
{
	solve();
	return 0;
}

Submission Info

Judge Result