Submission #333821

#	Time	Username	Problem	Language	Result	Execution time	Memory
333821		limabeans	Star triangles (IZhO11_triangle)	C++17	100 / 100	424 ms	5868 KiB

triangle

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

template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl





using ll = long long;




int n;
vector<pair<int,int>> a;

map<int,int> onx, ony;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);  cout.tie(0);

    cin>>n;
    a.resize(n);
    for (int i=0; i<n; i++) {
	cin>>a[i].first>>a[i].second;
	onx[a[i].first]++;
	ony[a[i].second]++;
    }


    ll res = 0;

    for (auto p: a) {
	res += 1ll*(onx[p.first]-1)*(ony[p.second]-1);
    }


    cout<<res<<endl;    
    return 0;
}

• Subtask 1: 100 / 100