Submission #975623

#	Time	Username	Problem	Language	Result	Execution time	Memory
975623		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	375 ms	9224 KiB

triangle

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define F first
#define S second
#define pll pair<ll, ll>
#define v(a) vector<a>

int main(){
    ll n; cin >> n;
    map<ll, ll> x, y;
    v(pll) arr(n);
    for(int i = 0; i < n; i++){
        cin >> arr[i].F >> arr[i].S;
        x[arr[i].F]++; y[arr[i].S]++;
    }

    ll ans = 0;
    for(int i = 0; i < n; i++){
        ll xx = x[arr[i].F]-1, yy = y[arr[i].S]-1;
        ans += (xx*yy);
    }

    cout << ans;
}

• Subtask 1: 100 / 100