Cod sursa(job #1750664)

Utilizator lflorin29Florin Laiu lflorin29 Data 30 august 2016 18:34:46
Problema Triplete Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.6 kb
#include <bits/stdc++.h>

using namespace std;
const int MAXN = 4096;

bitset<MAXN>cun[MAXN];
vector <int> lista[MAXN];

void baga (int x, int y) {
	cun[x][y] = cun[y][x] = 1;}

int main() {
	ifstream cin("triplete.in");
	ofstream cout("triplete.out");

	int N, M;

	cin >> N >> M;

	for (int i = 0, x, y; i < M; ++i)
	{
		cin >> x >> y;
		-- x; -- y;
		baga(x, y);
		lista[x].push_back(y);
		lista[y].push_back(x);
	}

	long long ans = 0;

	for (int i = 0; i < N ; ++i)
	{
		for(auto j : lista[i])
			ans += (cun[i] & cun[j]).count();
	}

	cout << ans / 6;
	return 0;
}