Submission #863512

#	Time	Username	Problem	Language	Result	Execution time	Memory
863512		Mizo_Compiler	Inside information (BOI21_servers)	C++17	50 / 100	3598 ms	33804 KiB

servers

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double ld;
#define pb push_back
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define F first
#define S second
const int N = 120005;
int n, pr[N], sz[N], q, dep[N], p[N][17], mn[N], vt[N];
int mx[N];
vector<array<int, 3>> qr;
vector<pair<int, int>> adj[N];
int findp(int u) {
	return pr[u] = (pr[u] == u ? u : findp(pr[u]));
}

void merge(int u, int v) {
	u = findp(u), v = findp(v);
	if (u == v)return;
	if (sz[u] < sz[v])swap(u, v);
	sz[u] += sz[v];
	pr[v] = u;
}

void init(int u, int par) {
	for (auto &[v, t] : adj[u]) {
		if (v == par)continue;
		p[v][0] = u;
		dep[v] = dep[u]+1;
		vt[v] = t;
		mn[v] = (vt[v] < vt[u] ? mn[u] : u);
		mx[v] = (vt[v] > vt[u] ? mx[u] : u);
		for (int i = 1; i < 17; i++) {
			p[v][i] = p[p[v][i-1]][i-1];
		}
		init(v, u);
	}
}

int lift(int u, int k) {
	for (int i = 0; i < 17; i++) {
		if ((k & (1 << i)))u = p[u][i];
	}
	return u;
}

int lca(int u, int v) {
	if (dep[u] < dep[v])swap(u, v);
	u = lift(u, dep[u]-dep[v]);
	if (u == v)return u;
	for (int i = 16; i >= 0; i--) {
		if (p[u][i] != p[v][i]) {
			u = p[u][i];
			v = p[v][i];
		}
	}
	return p[u][0];
}

bool sol(int u, int v) {
	if (findp(u) != findp(v))return false;
	int l = lca(u, v);
	if (dep[mx[u]] > dep[l])return false;
	if (dep[mn[v]] > dep[l])return false;
	if (l == v || l == u)return true;
	u = lift(u, dep[u]-dep[l]-1);
	v = lift(v, dep[v]-dep[l]-1);
	return (vt[v] < vt[u]);
}

int main () {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n >> q;
	for (int i = 0; i < n; i++) {
		pr[i] = i, sz[i] = 1;
	}
	q += n-1;
	for (int i = 0; i < q; i++) {
		char c;
		cin >> c;
		if (c == 'S') {
			int u, v;
			cin >> u >> v;
			--u, --v;
			qr.pb({0, u, v});
			adj[u].pb({v, i});
			adj[v].pb({u, i});
		} else if (c == 'Q') {
			int u, v;
			cin >> u >> v;
			--u, --v;
			qr.pb({1, u, v});
		} else {
			int u;
			cin >> u;
			--u;
			qr.pb({2, u, u});
		}
	}
	vt[0] = q+5;
	init(0, 0);
	for (auto &[op, u, v] : qr) {
		if (!op)merge(u, v);
		else if (op == 1) {
			cout << (sol(u, v) ? "yes\n" : "no\n");
		} else {
			int cnt = 0;
			for (int i = 0; i < n; i++) {
				cnt += sol(i, u);
			}
			cout << cnt << "\n";
		}
	}
}

• Subtask 1: 2.5 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 0 / 5
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 17.5 / 17.5
• Subtask 12: 0 / 17.5