제출 #725012

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
725012		Sohsoh84	철인 이종 경기 (APIO18_duathlon)	C++17	23 / 100	125 ms	66756 KiB

count_triplets

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 1e6 + 10;

int n, m, H[MAXN], tin[MAXN], low[MAXN], t, cnt, sz[MAXN];
stack<int> st;
vector<int> adj[MAXN], G[MAXN];
bool vis[MAXN];
ll ans = 0;

void dfs(int v, int p) {
	st.push(v);
	tin[v] = low[v] = t++;
	for (int u : adj[v]) {
		if (u == p) continue;
		if (tin[u]) low[v] = min(low[v], tin[u]);
		else {
			dfs(u, v);
			low[v] = min(low[v], low[u]);
			if (low[u] >= tin[v]) {
				cnt++;
				G[v].push_back(n + cnt);
				while (G[n + cnt].empty() || G[n + cnt].back() != u) {
					G[n + cnt].push_back(st.top());
					st.pop();
				}
			}
		}
	}
}

void solve(int v) {
	if (v <= n) sz[v] = 1;
	for (int u : G[v]) {
		solve(u);
		sz[v] += sz[u];
		if (v > n) ans -= 1ll * sz[u] * (sz[u] - 1) * G[v].size();
	}

	if (v > n) ans -= 1ll * (t - sz[v]) * (t - sz[v] - 1) * G[v].size();
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> m;
	for (int i = 1; i <= m; i++) {
		int u, v;
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}

	for (int i = 1; i <= n; i++) {
		if (tin[i]) continue;
		t = 0;
		dfs(i, 0);

		ans += 1ll * t * (t - 1) * (t - 2);
		solve(i);
	}

	cout << ans << endl;
	return 0;
}

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