Submission #1235653

#	Time	Username	Problem	Language	Result	Execution time	Memory
1235653		Ghulam_Junaid	Thousands Islands (IOI22_islands)	C++20	11.90 / 100	83 ms	11080 KiB

islands

#include <bits/stdc++.h>
#include "islands.h"
// #include "grader.cpp"
using namespace std;

const int N = 2e5 + 10;
int n, m, vis[N], bad[N], good[N];
vector<int> g[N], V;

vector<int> seen;
bool dfs(int v){
    if (good[v] or v == 0) return 1;
    if (bad[v]) return 0;

    seen.push_back(v);
    vis[v] = 1;
    bool ans = 0;
    for (int e : g[v]){
        int u = V[e];
        if (vis[u] == 2) continue;
        if (vis[u] == 1) ans = 1;
        else ans |= dfs(u);
    }
    vis[v] = 2;
    if (ans) good[v] = 1;
    else bad[v] = 1;
    return ans;
}

variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> vv) {
    V = vv;
    n = N, m = M;
    for (int i = 0; i < m; i ++){
        g[U[i]].push_back(i);
    }
    int ans = 0;
    for (int e : g[0]){
        memset(vis, 0, sizeof vis);
        ans += dfs(V[e]);
        if (ans >= 2) return true;
    }
    return false;
}

• Subtask 1: 1.75 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 0 / 21
• Subtask 4: 8.4 / 24
• Subtask 5: 0 / 45