Submission #975869

#	Time	Username	Problem	Language	Result	Execution time	Memory
975869		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	205 ms	11808 KiB

triangle

#include<bits/stdc++.h>
using namespace std;
int main() {
    int N;
    cin >> N;
    unordered_map<int, int> xCount, yCount;
    vector<pair<int, int>> points(N);
    for (int i = 0; i < N; ++i) {
        int x, y;
        cin >> x >> y;
        points[i] = make_pair(x, y);
        xCount[x]++;
        yCount[y]++;
    }
    long long totalCount = 0;
    for (auto point : points) {
        int x = point.first;
        int y = point.second;
        int sameX = xCount[x];
        int sameY = yCount[y];
        totalCount += (long long)(sameX - 1) * (sameY - 1);
    }
    cout << totalCount << endl;

    return 0;
}

• Subtask 1: 100 / 100