제출 #563196

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
563196		hollwo_pelw	철인 이종 경기 (APIO18_duathlon)	C++17	100 / 100	138 ms	31704 KiB

count_triplets

#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/trie_policy.hpp>
// #include <ext/rope>

using namespace std;
// using namespace __gnu_cxx;
// using namespace __gnu_pbds;

void Hollwo_Pelw();

signed main(){
#ifndef hollwo_pelw_local
	if (fopen(".inp", "r"))
		assert(freopen(".inp", "r", stdin)), assert(freopen(".out", "w", stdout));
#else
	using namespace chrono;
	auto start = steady_clock::now();
#endif
	cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
	int testcases = 1;
	// cin >> testcases;
	for (int test = 1; test <= testcases; test++){
		// cout << "Case #" << test << ": ";
		Hollwo_Pelw();
	}
#ifdef hollwo_pelw_local
	auto end = steady_clock::now();
	cout << "\nExecution time : " << duration_cast<milliseconds> (end - start).count() << "[ms]" << endl;
#endif
}

const int N = 2e5 + 5;

int n, m, nnode, tin[N], low[N], timer, st[N], top, siz[N], total;
vector<int> adj[N], g[N];

void tarjan(int u, int p) {
	st[++ top] = u, ++ total;
	
	tin[u] = low[u] = ++ timer;

	for (int v : g[u]) if (v != p) {
		if (tin[v]) {
			low[u] = min(low[u], tin[v]);
		} else {
			tarjan(v, u);
			low[u] = min(low[u], low[v]);

			if (low[v] >= tin[u]) {
				++ nnode;
				while (true) {
					int x = st[top --];
					adj[nnode].push_back(x);
					adj[x].push_back(nnode);
					if (x == v) break;
				}
				adj[nnode].push_back(u);
				adj[u].push_back(nnode);
			}
		}
	}
}

long long res;

void __solve__(int u, int p) {
	siz[u] = (u <= n);

	long long art = 0;
	for (int v : adj[u]) if (v != p) {
		__solve__(v, u), siz[u] += siz[v], ++ art;
	}

	if (u > n) {
		for (int v : adj[u]) {
			if (v != p) {
				res -= 1ll * siz[v] * (siz[v] - 1) * art;
			} else {
				res -= 1ll * (total - siz[u]) * (total - siz[u] - 1) * art;
			}
		}
	}

}

void Hollwo_Pelw(){
	cin >> n >> m, nnode = n;
	for (int u, v; m --; ) {
		cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	for (int i = 1; i <= n; i++) if (!tin[i]) {
		total = 0, tarjan(i, 0);
		res += 1ll * total * (total - 1) * (total - 2);
		__solve__(i, 0);
	}
	cout << res << '\n';
}

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