Submission #975001

#	Time	Username	Problem	Language	Result	Execution time	Memory
975001		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	83 ms	5484 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL);
#define ll long long
#define rep(i, n) for(int i = 0 ; i < n ; i++)
#define all(a) a.begin(), a.end()

unordered_map<int, int> X;
unordered_map<int, int> Y;

int main() {
    fast

    int n; cin>>n;
    pair<int, int> coor[n+1];
    rep(i, n){
        int x, y; cin>>x>>y;
        X[x]++;
        Y[y]++;
        coor[i+1].first = x;
        coor[i+1].second = y;
    }
    ll ans = 0;
    for(int i = 1 ; i <= n ; i++){
        int x = coor[i].first;
        int y = coor[i].second;
        ans += (X[x] - 1)*(Y[y] - 1);
    }
    cout<<ans;
    
    return 0;
}

• Subtask 1: 100 / 100