Submission #621451

#	Time	Username	Problem	Language	Result	Execution time	Memory
621451		penguinhacker	Keys (IOI21_keys)	C++17	37 / 100	3054 ms	39744 KiB

keys

#include <bits/stdc++.h>
using namespace std;

#define ar array

const int mxN=3e5;
int n, m, sz[mxN], p[mxN];
vector<ar<int, 2>> adj[mxN];
bool dead[mxN], vis[mxN], has_key[mxN];
vector<int> by_color[mxN];

int find(int i) {
	return i^p[i]?p[i]=find(p[i]):i;
}

vector<int> find_reachable(vector<int> r, vector<int> u, vector<int> v, vector<int> c) {
	int n=r.size(), m=u.size();
	for (int i=0; i<m; ++i) {
		adj[u[i]].push_back({v[i], c[i]});
		adj[v[i]].push_back({u[i], c[i]});
	}
	memset(sz, 0x3f, sizeof(sz));
	iota(p, p+n, 0);
	while(count(dead, dead+n, 0)) {
		vector<ar<int, 2>> todo;
		for (int i=0; i<n; ++i) {
			if (dead[i])
				continue;
			vector<int> cmp(1, i);
			vis[i]=1;
			int found=-1;
			for (int j=0; j<cmp.size()&&found==-1; ++j) {
				int u=cmp[j];
				has_key[r[u]]=1;
				auto ck=[&](int v) {
					if (!vis[v]) {
						if (find(v)!=find(i))
							found=find(v);
						cmp.push_back(v);
						vis[v]=1;
					}
				};
				for (int v : by_color[r[u]])
					ck(v);
				by_color[r[u]].clear();
				for (ar<int, 2> v : adj[u]) {
					if (has_key[v[1]])
						ck(v[0]);
					else
						by_color[v[1]].push_back(v[0]);
				}
			}
			if (found==-1) {
				dead[i]=1;
				for (int j : cmp)
					sz[j]=cmp.size();
			} else if (dead[found]) {
				dead[i]=1;
			} else {
				todo.push_back({i, found});
			}
			for (int j : cmp) {
				vis[j]=0;
				for (ar<int, 2> v : adj[j])
					by_color[v[1]].clear();
				has_key[r[j]]=0;
			}
		}
		for (auto [u, v] : todo) {
			if (find(u)!=find(v)) {
				p[u]=v;
				dead[u]=1;
			}
		}
	}
	int mn=*min_element(sz, sz+n);
	vector<int> ans(n);
	for (int i=0; i<n; ++i)
		ans[i]=sz[i]==mn;
	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:32:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |    for (int j=0; j<cmp.size()&&found==-1; ++j) {
      |                  ~^~~~~~~~~~~

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