Submission #1100556

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100556		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	206 ms	5376 KiB

triangle

#include <bits/stdc++.h>
#define ll long long
using namespace std;
int main() {
    int n;
    cin>>n;
    unordered_map<int, int> cntx, cnty;
    pair<int, int> stars[n];
    for (int i = 0; i < n; i++) {
        int x, y;
        cin>>x>>y;
        stars[i] = {x, y};
        cntx[x]++;
        cnty[y]++;
    }
    ll total = 0;
    for (int i = 0; i < n; i++) {
        int x = stars[i].first;
        int y = stars[i].second;
        total += (cntx[x]-1) * (cnty[y]-1);
}
    cout<<total<<endl;
    return 0;
}

• Subtask 1: 100 / 100