제출 #721374

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
721374		NothingXD	철인 이종 경기 (APIO18_duathlon)	C++17	100 / 100	118 ms	50172 KiB

count_triplets

/*

   Wei Wai Wei Wai
   Zumigat nan damu dimi kwayt rayt

*/

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

typedef long long ll;
typedef double ld;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef complex<ld> point;
/*typedef __uint128_t L;
  struct FastMod {
  ull b, m;
  FastMod(ull b) : b(b), m(ull((L(1) << 64) / b)) {}
  ull reduce(ull a) {
  ull q = (ull)((L(m) * a) >> 64);
  ull r = a - q * b; // can be proven that 0 <= r < 2*b
  return r >= b ? r - b : r;
  }
  };
  FastMod FM(2);
  */
void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	cerr << " " << H;
	debug_out(T...);
}

#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
#define F first
#define S second

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2e5 + 10;
const int inf = 1e9;

int n, m, a[maxn], cnt[maxn], sz[maxn], st[maxn], lw[maxn], tme, cmcnt, vercnt;
vector<int> g[maxn], t[maxn], comp[maxn], stk, going;
bool vis[maxn], mark[maxn];
ll ans = 0;

void dfs(int v){
	lw[v] = st[v] = ++tme;
	vis[v] = true;
	going.push_back(v);
	stk.push_back(v);
	for (auto u: g[v]){
		if (!vis[u]){
			dfs(u);
			lw[v] = min(lw[v], lw[u]);
			if (lw[u] >= st[v]){
				if (st[v] > 1 || st[u] > 2) mark[v] = true;
				cmcnt++;
				comp[cmcnt].push_back(v);
				while(comp[cmcnt].back() != u){
					comp[cmcnt].push_back(stk.back());
					stk.pop_back();
				}
			}
		}
		else lw[v] = min(lw[v], st[u]);
	}
}

void solve(int v, int p = -1){
	vis[v] = true;
	sz[v] = cnt[v];
	for (auto u: t[v]){
		if (u != p){
			solve(u, v);
			sz[v] += sz[u];
		}
	}
}

void Calc(int v, int r, int p = -1){
	if (mark[v]){
		ans += 1ll * (sz[r] - 1) * (sz[r] - 2);
		for (auto u: t[v]){
			if (u != p){
				ans -= 1ll * sz[u] * (sz[u] - 1);
			}
			else{
				ans -= 1ll * (sz[r] - sz[v]) * (sz[r] - sz[v] - 1);
			}
		}

	}
	else{
		ans += 1ll * cnt[v] * (cnt[v]-1) * (cnt[v]-2);
		ans += 1ll * (sz[r] - cnt[v]) * (sz[r] - cnt[v] - 1) * (cnt[v] - 2 + (int)t[v].size());
		ans += 1ll * cnt[v] * (cnt[v] - 1) * ((int)t[v].size());
		for (auto u: t[v]){
			if (u != p){
				ans += 2ll * sz[u] * cnt[v] * ((int)t[v].size() - 1);
				ans += 2ll * sz[u] * cnt[v] * (cnt[v] - 1);
				ans -= 1ll * sz[u] * (sz[u] - 1) * (cnt[v] - 2 + (int)t[v].size());
			}
			else{
				ans += 2ll * (sz[r] - sz[v]) * cnt[v] * ((int)t[v].size() - 1);
				ans += 2ll * (sz[r] - sz[v]) * cnt[v] * (cnt[v] - 1);
				ans -= 1ll * (sz[r] - sz[v]) * (sz[r] - sz[v] - 1) * (cnt[v] - 2 + (int)t[v].size());
			}
		}
	}
	for (auto u: t[v]) if (u != p) Calc(u, r, v);
}


int main(){
	ios_base::sync_with_stdio(false); cin.tie(0);

	cin >> n >> m;
	for (int i = 1; i <= m; i++){
		int u, v; cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}

	for (int i = 1; i <= n; i++){
		if (!vis[i]){
			stk.clear();
			going.clear();
			tme = 0;
			dfs(i);
			if (going.size() == 1){
				cmcnt++;
				comp[cmcnt].push_back(i);
			}
		}
	}


	for (int i = 1; i <= cmcnt; i++){
		cnt[n+i] = comp[i].size();
		for (auto x: comp[i]){
			if (mark[x]){
				cnt[n+i]--;
				t[x].push_back(n+i);
				t[n+i].push_back(x);
			}
		}
	}


	memset(vis, false, sizeof vis);

	for (int i = 1; i <= n; i++) cnt[i] = 1;

	for (int i = 1; i <= cmcnt; i++){
		if (!vis[n+i]){
			solve(n+i);
			Calc(n+i, n+i);
		}
	}

	cout << ans << '\n';

	return 0;
}

• 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