Submission #991320

#	Time	Username	Problem	Language	Result	Execution time	Memory
991320		kelfert	Star triangles (IZhO11_triangle)	C++17	100 / 100	252 ms	12280 KiB

triangle

#pragma GCC optimize("O3")
#pragma GCC target("avx2")
#include <bits/stdc++.h>

using namespace std;

#define F first
#define S second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
typedef long long ll;

void solve() {
    int n; cin >> n;
    vector<pair<int, int> > p(n);
    map<int, int> cntx, cnty;
    for (int i = 0; i < n; i++) {
        cin >> p[i].F >> p[i].S;
        cntx[p[i].F]++;
        cnty[p[i].S]++;
    }
    
    ll ans = 0;
    for (int i = 0; i < n; i++) ans += (cntx[p[i].F] - 1) * (cnty[p[i].S] - 1);
    cout << ans;
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    solve();
    return 0;
}

• Subtask 1: 100 / 100