Submission #1173596

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173596		nguyenkhangninh99	Star triangles (IZhO11_triangle)	C++20	100 / 100	504 ms	23328 KiB

triangle

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

void solve(){
    int n; cin >> n;

    set<array<int, 2>> s;
    map<int, int> cntx, cnty;

    for(int i = 1; i <= n; i++){
        int x, y; cin >> x >> y;
        s.insert({x, y});
    }

    int res = 0;

    for(auto a: s) cntx[a[0]]++, cnty[a[1]]++;
    for(auto a: s) res += (cntx[a[0]] - 1) * (cnty[a[1]] - 1);
    
    cout << res;
}
 
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
 
    solve();
}

• Subtask 1: 100 / 100