отрицательные циклы

#include<iostream>
#include <vector>
using namespace std;

struct rebro
{
 int begin, end, ves;
 void new_rebro(int begin, int end, int ves)
 {
   this->begin = begin;
   this->end = end;
   this->ves = ves;
 }
};

class Graph
{
  private:
  int n, **arr, shet_reber, *path;
  rebro *vse_rebra;

  public:
  Graph (int **matrix, int x, int shet)
  {
    n = x;
    arr = matrix;
    shet_reber = shet;

    vse_rebra = new rebro[shet_reber];
    spisok();
  }
  void spisok();
  void poisk_cycles();
};

void Graph::spisok()
{
  int k = 0;

  for (int i = 0; i < n; i++)
   for (int j = 0; j < n; j++)
    if (arr[i][j] != 100000)
    {
      vse_rebra[k].new_rebro(i, j, arr[i][j]);
      k++;
    }
}

void Graph::poisk_cycles()
{
 path = new int[n];
 int *d = new int[n];
 int x;

 for (int i = 0; i < n; i++)
   {
     path[i] = -1;
     d[i] = 0;
   }

    for (int i = 0; i < n; ++i)
    {
     x = -1;
    for (int j = 0; j < shet_reber; ++j)

     if (d[vse_rebra[j].begin] > d[vse_rebra[j].end] + vse_rebra[j].ves)
      {
        d[vse_rebra[j].begin] = max (-1000000, d[vse_rebra[j].end] + vse_rebra[j].ves);
        path[vse_rebra[j].begin] = vse_rebra[j].end;
        x = vse_rebra[j].begin;
      }
  }

  if (x == -1)
    cout << "NO";
  else
  {
    cout << "YES" << endl;
    vector<int> cycle;

    int y = x;
        for (int i = 0; i < n; ++i)
            y = path[y];

        for (int cur = x; ; cur = path[cur])
        {
            cycle.push_back (cur);
            if (cur == y && cycle.size() > 1)
             break;
        }
    cout << cycle.size() << endl;
    for (int i = 0; i < cycle.size(); ++i)
      cout << cycle[i]+1 << " ";
  }
}

int main()
{
 int n, shet_reber = 0;
 cin >> n;

int **arr = new int*[n];

for ( int i = 0; i < n; i++)
     arr[i] = new int[n];

for (int i = 0; i < n; i++)
  for (int j = 0; j < n; j++)
      {
        cin >> arr[i][j];
        if (arr[i][j] != 100000)
         shet_reber++;
      }

 Graph object(arr, n, shet_reber);
 object.poisk_cycles();
}
6
0 -50 0 -34 0 0
0 0 -45 0 0 10
-28 0 0 0 0 0
0 0 -31 0 25 0
48 0 0 0 0 60
20 0 0 0 0 0