Submission #1108830

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108830		siewjh	Keys (IOI21_keys)	C++17	100 / 100	1633 ms	73648 KiB

keys

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 300005;
int keya[MAXN], p[MAXN], minv;
bool dead[MAXN];
vector<pair<int, int>> adj[MAXN];
set<int> ansl, recj;
int root(int x){
	if (p[x] == -1) return x;
	else return p[x] = root(p[x]);
}
void join(int ra, int rb){
	p[ra] = rb;
}
void search(int st){
	queue<int> q; map<int, vector<int>> lckm; set<int> ks, pro;
	q.push(st);
	while (!q.empty()){
		int x = q.front(); q.pop();
		int rx = root(x);
		if (rx == st){
			if (pro.count(x)) continue;
			pro.insert(x);
			if (!ks.count(keya[x])){
				ks.insert(keya[x]);
				for (int nn : lckm[keya[x]]) q.push(nn);
				lckm.erase(keya[x]);
			}
			for (auto [nn, nt] : adj[x]){
				if (ks.count(nt)) q.push(nn);
				else lckm[nt].push_back(nn);
			}
		}
		else{
			join(st, rx);
			recj.insert(rx);
			return;
		}
	}
	dead[st] = 1;
	if (pro.size() < minv){
		minv = pro.size();
		ansl.clear();
		for (int x : pro) ansl.insert(x);
	}
	else if (pro.size() == minv){
		for (int x : pro) ansl.insert(x);
	}
}
vector<int> find_reachable(vector<int> key, vector<int> u, vector<int> v, vector<int> lock){
	int nodes = key.size(), edges = lock.size();
	for (int i = 0; i < nodes; i++){
		keya[i] = key[i]; p[i] = -1;
	}
	for (int i = 0; i < edges; i++){
		int a = u[i], b = v[i], c = lock[i];
		adj[a].push_back({b, c});
		adj[b].push_back({a, c});
	}
	minv = MAXN;
	while (true){
		bool run = 0;
		recj.clear();
		for (int i = 0; i < nodes; i++){
			if (root(i) != i || dead[i] || recj.count(i)) continue;
			run = 1;
			search(i);
		}
		if (!run) break;
	}
	vector<int> ans(nodes, 0);
	for (int x : ansl) ans[x] = 1;
	return ans;
}

Compilation message (stderr)

keys.cpp: In function 'void search(int)':
keys.cpp:41:17: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   41 |  if (pro.size() < minv){
      |      ~~~~~~~~~~~^~~~~~
keys.cpp:46:22: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   46 |  else if (pro.size() == minv){
      |           ~~~~~~~~~~~^~~~~~~

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