Submission #330840

#	Time	Username	Problem	Language	Result	Execution time	Memory
330840		Batyr	Star triangles (IZhO11_triangle)	C++17	100 / 100	700 ms	15724 KiB

triangle

#include <bits/stdc++.h>

#define inf 1000000007
#define N 1000007
#define pb push_back
#define ss second
#define ff first
#define pii pair<ll,ll>
#define ll long long

using namespace std;
const int maxn = 3e5+5;
ll n,ans;
pii a[maxn];
map<ll, ll> m,k;
int main() {
	cin >> n;

	for (int i = 1; i <= n; ++i){
		cin >> a[i].ff >> a[i].ss;
		m[a[i].ff]++;
		k[a[i].ss]++;
	}

	for (int i = 1; i <= n; ++i){
		ans += (m[a[i].ff] - 1) * (k[a[i].ss] - 1);
	}

	cout << ans << "\n";
}

• Subtask 1: 100 / 100