Submission #447216

#	Time	Username	Problem	Language	Result	Execution time	Memory
447216		hhhhaura	Inside information (BOI21_servers)	C++14	100 / 100	1004 ms	51496 KiB

servers

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma loop-opt(on)
#define rep(i, a, b) for(int i = a; i <= b; i ++)
#define all(x) x.begin(), x.end()

#define INF 1000000000
#define MOD 1000000007
#define eps (1e-9)

using namespace std;
#define pii pair<int, int>
struct BIT {
	int n;
	vector<int> v;
	stack<pii> ops;
	void init_(int _n) {
		n = _n;
		v.assign(n + 1, 0);
	}
	int lowbit(int x) { return x & (-x); }
	void modify(int x, int val) {
		if(x == 0) return;
		if(val > 0) ops.push({x, val});
		for(int i = x; i <= n; i += lowbit(i)) {
			v[i] += val;
		}
	}
	int query(int x) {
		int ans = 0;
		for(int i = x; i > 0; i -= lowbit(i)) {
			ans += v[i];
		}
		return ans;
	}
	int ask(int x) {
		return query(n) - query(x - 1);
	}
	void undo() {
		while(ops.size()) {
			pii cur = ops.top(); ops.pop();
			modify(cur.first, -cur.second);
		}
	}
};

namespace solver {
	int n, k;
	BIT bit;
	vector<int> vis, mx, sz, R, ch;
	vector<int> L, J, es, cost, t, ans, tp;
	vector<pii> a;
	vector<vector<pii>> nxt;
	vector<vector<int>> mp;
	void init_(int _n, int _k) {
		n = _n, k = _k;
		bit.init_(n + k);
		vis.assign(n + 1, 0);
		mx.assign(n + 1, 0);
		sz.assign(n + 1, 0);
		R.assign(n + 1, 0);
		L.assign(n + 1, 0);
		J.assign(n + 1, 0);
		
		es.assign(1, 0);
		cost.assign(1, INF);
		ch.clear();
		
		tp.assign(k + 1, 0);
		a.assign(k + 1, {0, 0});
		ans.assign(k + 1, 0);
		t.assign(k + 1, 0);
		nxt.assign(n + 1, vector<pii>());
		mp.assign(n + 1, vector<int>());
	}
	void add_edge(int a, int b, int c) {
		mp[a].push_back(es.size());
		mp[b].push_back(es.size());
		es.push_back(a ^ b);
		cost.push_back(c);
	}
	void get_sz(int x, int par) {
		mx[x] = 0, sz[x] = 1;
		for(auto i : mp[x]) if(i != par) {
			int to = es[i] ^ x;
			if(vis[to]) continue;
			get_sz(to, i);
			sz[x] += sz[to];
			mx[x] = max(mx[x], sz[to]);
		}
	}
	int get_cen(int x, int par, int tot) {
		int best = x;
		for(auto i : mp[x]) if(i != par) {
			int to = es[i] ^ x;
			if(vis[to]) continue;
			int cur = get_cen(to, i, tot);
			if(max(mx[cur], tot - sz[cur]) < 
				max(mx[best], tot - sz[best])) best = cur;
		}
		return best;
	}
	void dfs(int x, int par, int l, int j, int r) {
		J[x] = j, L[x] = l, R[x] = r;
		ch.push_back(x);
		for(auto i : mp[x]) if(i != par) {
			int to = es[i] ^ x;
			if(vis[to]) continue;
			dfs(to, i, l,
				(cost[par] > cost[i] ? j : INF), 
				(cost[par] < cost[i] ? max(cost[i], r) : INF)
			);
		}
	}
	void deco(int x, vector<pii> q) {
		ch.clear();
		get_sz(x, -1);
		int c = get_cen(x, -1, sz[x]);
		vis[c] = 1;
		R[c] = J[c] = L[c] = 0;
		vector<vector<pii>> temp(mp[c].size(), vector<pii>());
		for(auto i : mp[c]) {
			int to = es[i] ^ c;
			if(vis[to]) continue;
			nxt[i].clear();
			dfs(to, i, i, cost[i], cost[i]);
		}
		vector<pii> s;
		for(auto i : q) {
			if(i.first == 1) {
				int x, y; tie(x, y) = a[i.second];
				if(L[x] == L[y]) nxt[L[x]].push_back(i);
				else if(x == c) ans[i.second] = (t[i.second] > J[y]);	
				else if(y == c) ans[i.second] = (t[i.second] > R[x]);	
				else ans[i.second] = (J[y] < cost[L[x]] && t[i.second] > R[x]);	
			}
			else s.push_back({0, i.second});
		}
		for(auto i : ch) s.push_back({1, i});
		sort(all(s), [](pii a, pii b) {
			int t1 = (a.first? R[a.second] : t[a.second]);
			int t2 = (b.first? R[b.second] : t[b.second]);
			return t1 < t2;
		});			 
		for(auto i : s) {
			if(i.first) bit.modify(min(n + k, cost[L[i.second]]), 1);
			else {
				int x = a[i.second].first;
				ans[i.second] += bit.ask(min(J[x] + 1, n + k + 1)) + (J[x] < t[i.second]);
				if(x != c) nxt[L[x]].push_back({2, i.second});
			}
 		}
		bit.undo();
		rep(i, 0, signed(mp[c].size()) - 1) {
			temp[i].swap(nxt[mp[c][i]]);
		}
		rep(i, 0, signed(mp[c].size()) - 1) {
			int e = mp[c][i], to = es[e] ^ c;
			if(vis[to]) continue;
			deco(to, temp[i]);
		}
		return;
	}
};
using namespace solver;
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	int n, k, cur = 0; 
	cin >> n >> k;
	init_(n, k);
	vector<pii> q;
	rep(i, 1, n + k - 1) {
		char c; cin >> c;
		if(c == 'S') {
			int x, y; cin >> x >> y;
			add_edge(x, y, i);
		}
		else if(c == 'Q') {
			int x, y; cin >> x >> y;
			a[++cur] = {x, y};
			tp[cur] = 1, t[cur] = i;
			if(x == y) ans[cur] = 1;
			else q.push_back({1, cur});
		}
		else {
			int x; cin >> x;
			a[++cur] = {x, -1};
			tp[cur] = 2, t[cur] = i;
			q.push_back({2, cur});
		} 
	}
	deco(1, q);
	rep(i, 1, k) {
		if(tp[i] == 1) cout << (ans[i] ? "yes" : "no") << "\n";
		else cout << ans[i] << "\n";
	}
	return 0;
}
/*
6 9
S 1 2
S 1 3
S 3 4
Q 5 1
S 4 5
S 1 6
Q 5 1
Q 1 5
C 1
C 2
C 3
C 4
C 5
C 6
*/

Compilation message (stderr)

servers.cpp:3: warning: ignoring '#pragma loop ' [-Wunknown-pragmas]
    3 | #pragma loop-opt(on)
      |

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