Snakeless path

input/code.cpp: In function 'void dfs(std::vector<std::vector<int> >&, int, int, std::vector<bool>&, std::vector<int>&, bool&)':
input/code.cpp:19:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |         for (int neighbor = 0; neighbor < adj.size(); neighbor++) {
      |                                ~~~~~~~~~^~~~~~~~~~~~

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

void dfs(vector<vector<int>>& adj, int start, int end, vector<bool>& visited, vector<int>& path, bool &sol_found) 
{
    if (start == end) {
        sol_found = true;
        // Print sol
        cout << path.size() << endl;
        for (auto land : path) {
            cout << land + 1 << " ";
        }
        cout << endl;
    }
    else {
        for (int neighbor = 0; neighbor < adj.size(); neighbor++) {
            if (adj[start][neighbor] == 1 and !visited[neighbor])
            {
                // Mark as visited
                visited[neighbor] = true;
                path.push_back(neighbor);

                // Recursive
                dfs(adj, neighbor, end, visited, path, sol_found);

                // Reestart state
                path.pop_back();
                visited[neighbor] = false;
            }
        }
    }
}

int main() {
    int n, m;
    cin >> n >> m;

    // Adj=1 if there is an edge
    vector<vector<int>> adj(n, vector<int>(n, 1));

    // Delete those edges with snakes
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        adj[u-1][v-1] = 0;
    }

    // Find a path from 0 to n-1
    vector<bool> visited(n, false);
    vector<int> path;
    visited[0] = true;
    path.push_back(0);
    bool sol_found = false;
    dfs(adj, 0, n - 1, visited, path, sol_found);
    if (!sol_found) {
        cout << 0 << endl;
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: WRONG ANSWER

Test 29

Verdict: ACCEPTED

Test 30

Verdict: TIME LIMIT EXCEEDED

Test 31

Verdict: TIME LIMIT EXCEEDED

Test 32

Verdict: TIME LIMIT EXCEEDED

Test 33

Verdict: TIME LIMIT EXCEEDED

Test 34

Verdict: TIME LIMIT EXCEEDED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: OUTPUT LIMIT EXCEEDED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: TIME LIMIT EXCEEDED

Test 41

Verdict: TIME LIMIT EXCEEDED

Test 42

Verdict: TIME LIMIT EXCEEDED

Test 43

Verdict: TIME LIMIT EXCEEDED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: OUTPUT LIMIT EXCEEDED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: TIME LIMIT EXCEEDED

Test 51

Verdict: TIME LIMIT EXCEEDED

Test 52

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Test 53

Verdict: TIME LIMIT EXCEEDED

Test 54

Verdict: TIME LIMIT EXCEEDED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: OUTPUT LIMIT EXCEEDED

Test 57

Verdict: ACCEPTED

Test 58

Verdict: TIME LIMIT EXCEEDED

Test 59

Verdict: ACCEPTED

Test 60

Verdict: OUTPUT LIMIT EXCEEDED

Test 61

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Test 62

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Test 63

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Test 64

Verdict: TIME LIMIT EXCEEDED

Test 65

Verdict: OUTPUT LIMIT EXCEEDED

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: TIME LIMIT EXCEEDED

Test 69

Verdict: ACCEPTED

Test 70

Verdict: RUNTIME ERROR

Test 71

Verdict: RUNTIME ERROR

Test 72

Verdict: RUNTIME ERROR

Test 73

Verdict: RUNTIME ERROR

Test 74

Verdict: RUNTIME ERROR

Test 75

Verdict: RUNTIME ERROR

Test 76

Verdict: RUNTIME ERROR

Test 77

Verdict: RUNTIME ERROR

Test 78

Verdict: RUNTIME ERROR

Test 79

Verdict: RUNTIME ERROR

Test 80

Verdict: RUNTIME ERROR

Test 81

Verdict: RUNTIME ERROR

Test 82

Verdict: RUNTIME ERROR

Test 83

Verdict: RUNTIME ERROR

Test 84

Verdict: RUNTIME ERROR

Test 85

Verdict: RUNTIME ERROR

Test 86

Verdict: RUNTIME ERROR

Test 87

Verdict: RUNTIME ERROR

Test 88

Verdict: RUNTIME ERROR

Test 89

Verdict: RUNTIME ERROR