dfs_one_way

#include <iostream>
#include <deque>
#include <algorithm>
#include <vector>
#include <vector>
#include <fstream>
#include <ctime>

using namespace std;

bool m[100][100];
bool used[100];
deque<int>best_path;
deque<int>path;
bool done = false;

void dfs(int i, int to, int n){
    used[i] = true;
    path.push_back(i);
    if(i == to){
        best_path = path;
        done = true;
    }
    else {
        for(int j = 0; j<n; j++){
            if(m[i][j] && !used[j] && !done){
                dfs(j,to,n);
            }
        }
    }
    path.pop_back();
}

ostream& operator<<(ostream& os, vector<int>a){
    for(int i = 0; i<a.size(); i++){
        os<<a[i]<<" ";
    }
    return os;
}

ostream& operator<<(ostream& os, deque<int>a){
    for(int i = 0; i<a.size(); i++){
        os<<a[i]<<" ";
    }
    return os;
}

int main()
{
    //string s = "D://Studying/C/Tools/QtCreator/bin/dfs/test.txt";
    string s = "D://Shmyginds/for_c++/olympy/test.txt";
    ifstream fin(s.c_str());
    int n;

    int from, to;
    cin>>n>>from>>to;
    for(int i = 0; i<n; i++){
        used[i] = false;
        for(int j = 0; j<n; j++){
            m[i][j] = false;
        }
    }
    for(int i = 0; i<n; i++){
        for(int j = 0; j<n; j++){
            fin>>m[i][j];
            cout<<m[i][j]<<" ";
            //cin>>m[i][j];
        }
        cout<<endl;
    }
    dfs(from-1, to-1, n);
    int steps;
    if(best_path.size()>0){
        steps = best_path.size()-1;
        for(int i = 0; i<best_path.size(); i++){
            best_path[i]++;
        }
        cout<<steps<<endl;
        cout<<best_path;
    }
    else{
        cout<<-1;
    }
    return 0;
}