Submission #521587

#	Time	Username	Problem	Language	Result	Execution time	Memory
521587		eecs	Keys (IOI21_keys)	C++17	0 / 100	1 ms	292 KiB

keys

#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);
    iota(perm.begin(), perm.end(), 0);
    shuffle(perm.begin(), perm.end(), mt19937(time(0)));
    queue<int> Q;
    vector<bool> solved(n);
    for (int x : perm) {
        vector<int> V = {x};
        Q.push(x), vis[x] = visc[r[x]] = x, solved[x] = 1;
        while (!Q.empty()) {
            int u = Q.front(); Q.pop();
            for (auto &e : G[u]) if (vis[e[0]] != x && visc[e[1]] == x) {
                V.push_back(e[0]);
                if (solved[e[0]] || !ans.empty() && V.size() > ans.size()) goto nxt;
                Q.push(e[0]), vis[e[0]] = visc[r[e[0]]] = x;
            }
        }
        if (V.size() < ans.size()) ans = V;
        else copy(V.begin(), V.end(), back_inserter(ans));
    nxt:;
    }
    vector<int> res(n);
    for (int x : ans) res[x] = 1;
    return res;
}

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:8:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     for (int i = 0; i < U.size(); i++) {
      |                     ~~^~~~~~~~~~
keys.cpp:24:50: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   24 |                 if (solved[e[0]] || !ans.empty() && V.size() > ans.size()) goto nxt;
      |                                     ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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