Submission #1070958

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070958		pawned	Duathlon (APIO18_duathlon)	C++17	8 / 100	33 ms	10592 KiB

count_triplets

#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")

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

#define fi first
#define se second
#define pb push_back
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;

const char nl = '\n';

void fastIO() {
	ios::sync_with_stdio(false);
	cin.tie(0);
}

const int MAX = 1e5 + 5;

int N, M;

bool vis[MAX];
vi adj[MAX];

vi inc;

void dfs(int n) {
	vis[n] = true;
	inc.pb(n);
	for (int x : adj[n]) {
		if (!vis[x])
			dfs(x);
	}
}

int main() {
	fastIO();
	cin>>N>>M;
	for (int i = 0; i < M; i++) {
		int u, v;
		cin>>u>>v;
		u--; v--;
		adj[u].pb(v);
		adj[v].pb(u);
	}
	ll total = 0;
	for (int i = 0; i < N; i++) {
		if (!vis[i]) {
			inc.clear();
			dfs(i);
			ll K = inc.size();
			ll cnte = 0;
			for (int x : inc)
				cnte += adj[x].size();
			cnte /= 2;
			if (cnte == K - 1)
				total += (K * (K - 1) * (K - 2)) / 3;
			else
				total += (K * (K - 1) * (K - 2));
		}
	}
//	cout<<"ANSWER: ";
	cout<<total<<endl;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 8 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10