# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
521591 | eecs | Keys (IOI21_keys) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "keys.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> find_reachable(vector<int> r, vector<int> U, vector<int> V, vector<int> C) {
int n = r.size();
vector<vector<array<int, 2>>> G(n);
for (int i = 0; i < U.size(); i++) {
G[U[i]].push_back({V[i], C[i]});
G[V[i]].push_back({U[i], C[i]});
}
vector<int> ans, perm(n), vis(n, -1), visc(n, -1);
vector<vector<int>> cand(n);
iota(perm.begin(), perm.end(), 0);
shuffle(perm.begin(), perm.end(), mt19937(time(0)));
queue<int> Q;
vector<bool> solved(n);
vector<int> V, col;
for (int x : perm) {
V = {x}, col.clear();
Q.push(x), vis[x] = x, solved[x] = 1;
while (!Q.empty()) {
int u = Q.front(); Q.pop();
for (auto &e : G[u]) if (vis[e[0]] ^ x) {
if (visc[e[1]] == x) {
V.push_back(e[0]), Q.push(e[0]), vis[e[0]] = x;
if (solved[e[0]] || !ans.empty() && V.size() > ans.size()) goto nxt;
} else {
col.push_back(e[1]), cand[e[1]].push_back(e[0]);
}
}
if (!visc[r[u]]) {
visc[r[u]] = 1;
for (int v : cand[r[u]]) {
V.push_back(v), Q.push(v), vis[v] = x;
if (solved[v] || !ans.empty() && V.size() > ans.size()) goto nxt;
}
}
}
if (V.size() < ans.size()) ans = V;
else copy(V.begin(), V.end(), back_inserter(ans));
nxt:;
for (int c : col) cand[c].clear();
}
vector<int> res(n);
for (int x : ans) res[x] = 1;
return res;
}