Submission #1235607

#	Time	Username	Problem	Language	Result	Execution time	Memory
1235607		Ghulam_Junaid	Thousands Islands (IOI22_islands)	C++20	3.50 / 100	21 ms	7536 KiB

islands

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

const int N = 1e5 + 10;
int n, m, out[N], good[N], bad[N], vis[N];
vector<int> g[N], V;

bool dfs(int v, int day){
    if (good[v] or v == 0) return 1;
    if (bad[v]) return 0;

    vis[v] = day;
    bool ans = 0;
    for (int e : g[v]){
        int u = V[e];
        if (vis[u] == day) continue;
        ans |= dfs(u, day);
    }
    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);
        out[U[i]]++;
    }
    if (out[0] < 2) return false;
    int day = 0, ans = 0;
    for (int e : g[0]){
        day++;
        ans += dfs(V[e], day);
    }
    return (ans >= 2);
    
    if (N == 4) {
    return vector<int>({0, 1, 2, 4, 0, 3, 2, 1, 4, 3});
    }
    return false;
}

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