Submission #1056413

#	Time	Username	Problem	Language	Result	Execution time	Memory
1056413		vjudge1	Thousands Islands (IOI22_islands)	C++17	9.10 / 100	17 ms	4956 KiB

islands

#include "islands.h"

#include <variant>
#include <vector>
#include <bits/stdc++.h>

using namespace std;

using vi = vector<int>;

variant<bool, vi> find_journey(int n, int m, vi U, vi V) {
    vi InDeg(n, 0), OutDeg(n, 0);
    vector<vi> L(n);
    for(int i = 0; i < m; ++i) {
        L[U[i]].push_back(V[i]);
        ++OutDeg[U[i]];
        ++InDeg[V[i]];
    }
    bool ok = false;
    vi viz(n, 0);
    function<void(int, int)> dfs = [&](int u, int p) {
        if(ok) return;
        if(viz[u] == 2) return;
        if(viz[u] == 1) {
            ok = 1;
            return;
        }
        viz[u] = 1;
        int nrf = 0;
        for(auto it : L[u]) {
            if(it != p) {
                ++nrf;
                dfs(it, u);
            }
        }
        if(nrf > 1) {
            ok = true;
        }
        viz[u] = 2;
    };
    dfs(0, -1);
    return ok;
}

• Subtask 1: 0 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 7.35 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45