Submission #700176

#	Time	Username	Problem	Language	Result	Execution time	Memory
700176		pera	Star triangles (IZhO11_triangle)	C++14	100 / 100	287 ms	15644 KiB

triangle

#include<bits/stdc++.h>
#include<vector>

using namespace std;

#define pb push_back
#define ll long long
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()

const ll mod = 1e9 + 7 , N = 2e5 + 100;

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0),cout.tie(0);
	ll n;cin >> n;
	ll ans = 0;
	map<ll , ll> mx , my;
	vector<pair<ll , ll>> a(n + 1);
	for(int i = 1;i <= n;i ++){
		cin >> a[i].first >> a[i].second;
		++ mx[a[i].first];
		++ my[a[i].second];
	}
	for(int i = 1;i <= n;i ++){
		ans += (mx[a[i].first] - 1) * (my[a[i].second] - 1);
	}
	cout << ans << endl;
}

• Subtask 1: 100 / 100