제출 #586920

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
586920		pavement	Inside information (BOI21_servers)	C++17	67.50 / 100	3558 ms	118976 KiB

servers

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
#define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using db = double;
using ll = long long;
using ld = long double;
using ii = pair<int, int>;
using iii = tuple<int, int, int>;
using iiii = tuple<int, int, int, int>;
template<class key, class value = null_type, class cmp = less<key> >
using ordered_set = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;

int N, K, cent, tot_sz, sz[240005], A[240005], B[240005], inc[240005], down[240005], dep[240005], par[240005], anc[25][240005], wei[25][240005];
bool vis[240005];
char C[240005];
vector<ii> adj[240005], vec[240005];

int get_sizes(int n, int e = -1) {
	sz[n] = 1;
	for (auto [u, w] : adj[n]) if (u != e && !vis[u])
		sz[n] += get_sizes(u, n);
	return sz[n];
}

void get_centroid(int n, int e = -1) {
	int m = tot_sz - sz[n];
	for (auto [u, w] : adj[n]) if (u != e && !vis[u]) {
		get_centroid(u, n);
		m = max(m, sz[u]);
	}
	if (m <= tot_sz / 2) cent = n;
}

void dfs(int n, int e = -1, int prv = -1) {
	anc[0][n] = e;
	wei[0][n] = prv;
	for (int k = 1; k < 20; k++)
		if (anc[k - 1][n] != -1) {
			anc[k][n] = anc[k - 1][anc[k - 1][n]];
			wei[k][n] = max(wei[k - 1][n], wei[k - 1][anc[k - 1][n]]);
		}
	for (auto [u, w] : adj[n]) if (u != e) {
		dep[u] = dep[n] + 1;
		if (w < prv) inc[u] = inc[n], down[u] = n;
		else down[u] = down[n], inc[u] = n;
		dfs(u, n, w);
	}
}

bool qry(int u, int v, int t) {
	int ou = u, ov = v, m_w = 0;
	bool has_swap = 0;
	if (dep[u] > dep[v]) {
		swap(u, v);
		has_swap = 1;
	}
	for (int k = 19; k >= 0; k--)
		if (dep[v] - (1 << k) >= dep[u]) {
			m_w = max(m_w, wei[k][v]);
			v = anc[k][v];
		}
	if (u == v) {
		if (m_w > t) return 0;
		if (dep[ou] <= dep[ov]) return dep[down[ov]] <= dep[ou];
		else return dep[inc[ou]] <= dep[ov];
	}
	if (has_swap) swap(u, v);
	for (int k = 19; k >= 0; k--)
		if (anc[k][u] != anc[k][v]) {
			m_w = max({m_w, wei[k][u], wei[k][v]});
			u = anc[k][u];
			v = anc[k][v];
		}
	int lca = anc[0][u];
	m_w = max({m_w, wei[0][u], wei[0][v]});
	return m_w < t && dep[inc[ou]] <= dep[lca] && dep[down[ov]] <= dep[lca] && wei[0][u] < wei[0][v];
}

ii get_ends(int u, int v) {
	int ou = u, ov = v;
	bool has_swap = 0;
	assert(u != v);
	if (dep[u] > dep[v]) {
		swap(u, v);
		has_swap = 1;
	}
	for (int k = 19; k >= 0; k--)
		if (dep[v] - (1 << k) >= dep[u] + 1) v = anc[k][v];
	if (u == anc[0][v]) {
		auto ret = mp(wei[0][v], wei[0][has_swap ? ou : ov]);
		if (has_swap) swap(ret.first, ret.second);
		return ret;
	}
	auto ret = mp(wei[0][ou], wei[0][ov]);
	return ret;
}

void decomp(int n, int e = -1) {
	get_sizes(n);
	tot_sz = sz[n];
	cent = -1;
	get_centroid(n);
	assert(cent != -1);
	vis[cent] = 1;
	par[cent] = e;
	int orig_cent = cent;
	for (auto [u, w] : adj[cent]) if (!vis[u])
		decomp(u, orig_cent);
}

main() {
	memset(anc, -1, sizeof anc);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> N >> K;
	for (int i = 1; i <= N + K - 1; i++) {
		cin >> C[i];
		if (C[i] == 'S' || C[i] == 'Q') cin >> A[i] >> B[i];
		else cin >> A[i];
		if (C[i] == 'S') {
			adj[A[i]].eb(B[i], i);
			adj[B[i]].eb(A[i], i);
		}
	}
	inc[1] = down[1] = 1;
	dfs(1);
	decomp(1);
	for (int i = 1; i <= N; i++) {
		for (int u = par[i]; u != -1; u = par[u]) {
			if (qry(u, i, (int)1e9)) {
				auto curr = get_ends(u, i);
				vec[u].eb(curr.first, curr.second);
			}
		}
	}
	for (int i = 1; i <= N + K - 1; i++) {
		if (C[i] == 'Q') {
			if (qry(B[i], A[i], i)) cout << "yes\n";
			else cout << "no\n";
		} else if (C[i] == 'C') {
			int ans = 1;
			for (auto [x, y] : vec[A[i]])
				if (y < i) ans++;
			for (int u = par[A[i]]; u != -1; u = par[u]) {
				if (qry(A[i], u, i)) {
					auto curr = get_ends(A[i], u);
					ans++;
					for (auto [x, y] : vec[u])
						if (curr.second < x && y < i) ans++;
				}
			}
			cout << ans << '\n';
		}
	}
}

컴파일 시 표준 에러 (stderr) 메시지

servers.cpp:127:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  127 | main() {
      | ^~~~

• Subtask 1: 2.5 / 2.5
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• Subtask 3: 2.5 / 2.5
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• Subtask 12: 0 / 17.5