Submission #743145

#	Time	Username	Problem	Language	Result	Execution time	Memory
743145		t6twotwo	Keys (IOI21_keys)	C++17	37 / 100	3062 ms	33376 KiB

keys

#include "keys.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> get(vector<int> p) {
	int mn = *min_element(p.begin(), p.end());
	vector<int> ans(p.size());
	for (int i = 0; i < p.size(); i++) {
		ans[i] = p[i] == mn;
	}
	return ans;
}
std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
	int n = r.size();
	int m = c.size();
	vector<vector<pair<int, int>>> adj(n);
	for (int i = 0; i < m; i++) {
		adj[u[i]].emplace_back(v[i], c[i]);
		adj[v[i]].emplace_back(u[i], c[i]);
	}
	auto bfs = [&](int s) {
		vector<bool> vis(n);
		vector<bool> have(n);
		vector<vector<int>> w(n);
		queue<int> q;
		vis[s] = 1;
		q.push(s);
		int ans = 0;
		while (!q.empty()) {
			int x = q.front();
			q.pop();
			ans++;
			have[r[x]] = 1;
			for (int v : w[r[x]]) {
				if (!vis[v]) {
					vis[v] = 1;
					q.push(v);
				}
			}
			w[r[x]].clear();
			for (auto [y, z] : adj[x]) {
				if (have[z]) {
					if (!vis[y]) {
						vis[y] = 1;
						q.push(y);
					}
				} else {
					w[z].push_back(y);
				}
			}
		}
		return ans;
	};
	vector<vector<int>> dir(n);
	vector<vector<int>> rev(n);
	for (int x = 0; x < n; x++) {
		for (auto [y, z] : adj[x]) {
			if (r[x] == z) {
				dir[x].push_back(y);
				rev[y].push_back(x);
			}
		}
	}
	vector<bool> vis(n);
	vector<int> s;
	auto dfs1 = [&](auto dfs1, int x) -> void {
		vis[x] = 1;
		for (int y : dir[x]) {
			if (!vis[y]) {
				dfs1(dfs1, y);
			}
		}
		s.push_back(x);
	};
	for (int i = 0; i < n; i++) {
		if (!vis[i]) {
			dfs1(dfs1, i);
		}
	}
	vector<int> t;
	auto dfs = [&](auto dfs, int x) -> void {
		t.push_back(x);
		vis[x] = 1;
		for (int y : rev[x]) {
			if (!vis[y]) {
				dfs(dfs, y);
			}
		}
	};
	fill(vis.begin(), vis.end(), 0);
	vector<int> p(n, n + 1);
	for (int i = n - 1; i >= 0; i--) {
		if (!vis[s[i]]) {
			t.clear();
			dfs(dfs, s[i]);
			bool flag = 0;
			for (int x : t) {
				for (int y : dir[x]) {
					if (!vis[y]) {
						flag = 1;
					}
				}
			}	
			if (flag) {
				continue;
			}
			int cnt = bfs(s[i]);
			for (int x : t) {
				p[x] = cnt;
			}
		}
	}
	return get(p);
}

Compilation message (stderr)

keys.cpp: In function 'std::vector<int> get(std::vector<int>)':
keys.cpp:7:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |  for (int i = 0; i < p.size(); i++) {
      |                  ~~^~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 0 / 30
• Subtask 5: 0 / 33