Submission #986982

#	Time	Username	Problem	Language	Result	Execution time	Memory
986982		pedroslrey	Keys (IOI21_keys)	C++17	37 / 100	3019 ms	27588 KiB

keys

#include <bits/stdc++.h>
#include "keys.h"

using namespace std;

vector<int> find_reachable(vector<int> rs, vector<int> us, vector<int> vs, vector<int> cs) {
	int n = rs.size();

	vector<vector<pair<int, int>>> graph(n);
	for (int i = 0; i < us.size(); ++i) {
		graph[us[i]].emplace_back(vs[i], cs[i]);
		graph[vs[i]].emplace_back(us[i], cs[i]);
	}

	function<int (int)> test = [&graph, &rs, n](int s) {
		vector<vector<int>> waiting(n);
		vector<bool> found(n), marc(n);

		queue<int> q;
		q.push(s);

		int sz = 0;
		while (!q.empty()) {
			int u = q.front(); q.pop();

			++sz;
			if (!found[rs[u]]) {
				found[rs[u]] = true;
				for (int x: waiting[rs[u]]) if (!marc[x]) {
					marc[x] = true;
					q.push(x);
				}
			}

			for (auto [v, k]: graph[u]) if (!marc[v])
				if (found[k]) {
					marc[v] = true;
					q.push(v);
				}
				else waiting[k].push_back(v);
		}

		return sz;
	};

	vector<int> best{}; int val = 1e9;
	for (int i = 0; i < n; ++i) {
		int x = test(i);
		
		if (x < val) {
			best = vector<int>{i};
			val = x;
		}
		else if (x == val) best.push_back(i);
	}

	vector<int> ans(n);
	for (int x: best)
		ans[x] = 1;

	return ans;
}

Compilation message (stderr)

keys.cpp: In function 'std::vector<int> find_reachable(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
keys.cpp:10:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |  for (int i = 0; i < us.size(); ++i) {
      |                  ~~^~~~~~~~~~~
keys.cpp: In lambda function:
keys.cpp:35:35: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
   35 |    for (auto [v, k]: graph[u]) if (!marc[v])
      |                                   ^

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