Submission #1368817

#	Time	Username	Problem	Language	Result	Execution time	Memory
1368817		Newtonabc	Star triangles (IZhO11_triangle)	C++20	100 / 100	348 ms	8532 KiB

triangle

#include<bits/stdc++.h>
#define ll long long
using namespace std;
map<int,ll> mx,my;
int main(){
    int n; cin>>n;
    ll ans=0;
    vector<pair<int,int>> qr;
    for(int i=1;i<=n;i++){
        int x,y; cin>>x >>y;
        qr.push_back({x,y});
        mx[x]++,my[y]++;
    }
    for(auto [x,y]:qr){
        ans+=(mx[x]-1LL)*(my[y]-1LL);
    }
    cout<<ans;
}

• Subtask 1: 100 / 100