Submission #976427

#	Time	Username	Problem	Language	Result	Execution time	Memory
976427		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	285 ms	15448 KiB

triangle

#include <iostream>
#include <map>
#include <vector>
using namespace std;

int main() {
    cin.tie(0); ios::sync_with_stdio(false);
    int n;
    long long ans = 0;
    cin >> n;
    map<int, vector<int>> adjX;
    map<int, vector<int>> adjY;

    for (int i = 0, xi, yi; i < n; i++) {
        cin >> xi >> yi;
        adjX[xi].push_back(yi);
        adjY[yi].push_back(xi);
    }

    int numX;
    for (auto &[xi, adj] : adjX) {
        numX = adj.size() - 1;
        for (auto &yi : adj) {
            if (!adjY.count(yi)) continue;
            ans += numX * (adjY[yi].size() - 1);
        }
    }
    cout << ans;
}

• Subtask 1: 100 / 100