Submission #1246431

#	Time	Username	Problem	Language	Result	Execution time	Memory
1246431		12baater	Longest Trip (IOI23_longesttrip)	C++20	0 / 100	1085 ms	572 KiB

longesttrip

#include "longesttrip.h"
#include <vector>
#include <stack>
#include <iostream>

using namespace std;


vector<int> ADJ[257];

bool in_path[257];


int longest_length = 0;

int current_length = 0;

stack<int> path;

void dfs(int node, int parent) {
    if (in_path[node]) return;
    in_path[node] = true;
    current_length++;
    longest_length = max(longest_length, current_length);

    for (int child : ADJ[node]) {
        if (child == parent) continue;
        dfs(child, node);
    }
    in_path[node] = false;
    current_length--;
}


bool find_path(int node, int parent) {
    if (in_path[node]) return false;
    in_path[node] = true;
    path.push(node);
    current_length++;
    if (current_length == longest_length) {
        in_path[node] = false;
        return true;
    }

    for (int child : ADJ[node]) {
        if (child == parent) continue;
        if (find_path(child, node)) {
            in_path[node] = 0;
            return true;
        };
    }
    in_path[node] = false;
    current_length--;
    path.pop();
    return 0;
}

vector<int> longest_trip(int N, int D)
{
    for (int i = 0; i < N; i++) {
        ADJ[i].clear();
    }
    longest_length = 0;
    for (int i = 0; i < N-1; i++) {
        for (int j = i+1; j < N; j++) {
            if (are_connected({i}, {j})) {
                ADJ[i].push_back(j);
                ADJ[j].push_back(i);
            }
        }
    }

    for (int i = 0; i < N; i++) {
        current_length = 0;
        dfs(i, i);
    }
    for (int i = 0; i < N; i++) {
        find_path(i, i);
    }
    vector<int> ans;
    for (; !path.empty(); path.pop()) {
        ans.push_back(path.top());
    }

    return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 60