Submission #972844

#	Time	Username	Problem	Language	Result	Execution time	Memory
972844		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	393 ms	13820 KiB

triangle

#include <bits/stdc++.h>
 
using namespace std;
using ll = long long;
 
int main(){
    int N; cin >> N;
    vector<pair<int, int>>v(N);
    map<int, ll>cntX, cntY;
 
    for(auto &[x, y]: v){
        cin >> x >> y;
        cntX[x]++;
        cntY[y]++;
    }
 
    ll ans = 0;
 
    for(auto &[x, y]: v){
        ans += max(0LL, (cntX[x] - 1)*(cntY[y] - 1));
    }
 
    cout << ans << endl;
 
    return 0;
}

• Subtask 1: 100 / 100