Submission #1067203

#	Time	Username	Problem	Language	Result	Execution time	Memory
1067203		j_vdd16	Thousands Islands (IOI22_islands)	C++17	22.75 / 100	27 ms	5212 KiB

islands

#include "islands.h"

#include <variant>
#include <algorithm>
#include <bitset>
#include <cstdint>
#include <cstring>
#include <iostream>
#include <limits.h>
#include <math.h>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

//#define int long long
#define loop(X, N) for(int X = 0; X < (N); X++)
#define all(V) V.begin(), V.end()
#define rall(V) V.rbegin(), V.rend()

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<bool> vb;
typedef vector<vector<bool>> vvb;

typedef uint64_t u64;
typedef int64_t i64;

int n, m;
vvii adj;

vb vis;
vi succesPath;

bool success = false;
vi path;
int dfs2(int node, int parent) {
    if (vis[node]) {
        return 1;
    }
    
    vis[node] = true;

    int count = 0;
    vi validPaths;
    for (auto [child, idx] : adj[node]) {
        if (child == parent) continue;
        
        path.push_back(idx);
        int res = dfs2(child, node);
        path.pop_back();

        if (res >= 1 && count < 2) {
            count++;
            validPaths.push_back(idx);
        }
    }
    if (count >= 2 && !success) {
        success = true;
        succesPath = path;
        
        succesPath.push_back(validPaths[0]);
        succesPath.push_back(validPaths[0] ^ 1);
        succesPath.push_back(validPaths[1]);
        succesPath.push_back(validPaths[1] ^ 1);

        succesPath.push_back(validPaths[0] ^ 1);
        succesPath.push_back(validPaths[0]);
        succesPath.push_back(validPaths[1] ^ 1);
        succesPath.push_back(validPaths[1]);

        for (int i = path.size() - 1; i >= 0; i--) {
            succesPath.push_back(path[i]);
        }
    }

    return 1;
}

std::variant<bool, std::vector<int>> find_journey(int N, int M, vi U, vi V) {
    n = N;
    m = M;
    adj = vvii(n);
    loop(i, m) {
        adj[U[i]].push_back({V[i], i});
    }

    vis = vb(n);
    success = false;
    path = vi();
    dfs2(0, -1);

    if (success) {
        for (int x : succesPath) {
            cerr << x << ' ';
        }
        cerr << endl;
        return succesPath;
    }
    return false;

    // return false;

    // return success;
}

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