шахматный конь

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

const int inf = 1000;
struct kletka
{
 int x, y;
 void new_kletka(int x, int y)
 {
   this->x = x;
   this->y = y;
 }
};

class Graph
{
public:
    queue<kletka> Q;
    int n, m, dlina = 0, *dx, *dy;
    kletka start, finish, *itog;
    int **arr;

    Graph(int N, int M, int x1, int y1, int x2, int y2)
    {
        n = N;
        m = M;
        start.new_kletka(x1, y1);
        finish.new_kletka(x2, y2);

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

        for(int i = 0; i < n; i++)
         for (int j = 0; j < m; j++)
          arr[i][j] = inf;

        arr[x1][y1] = 0;

        dx = new int[8]{2, 2, 1, 1, -1, -1, -2, -2};
        dy = new int[8]{1, -1, 2, -2, 2, -2, 1, -1};
    }

    void smejnost();
    void all_way();
    void result();
    void negative() { cout << -1;};
};

void Graph::smejnost()
{
  int i, j, u = 0, v = 0;
  kletka a;
  Q.push(start);

  while(!Q.empty())
  {
   i = Q.front().x;
   j = Q.front().y;
   Q.pop();

   for(int k = 0; k < 8; ++k)
    {
      u = i + dx[k];
      v = j + dy[k];

      if(u >= 0 && u < n && v >= 0 && v < m && arr[u][v] > arr[i][j] + 1)
      {
       arr[u][v] = arr[i][j] + 1;
       a.new_kletka(u, v);
       Q.push(a);
      }
    }
  }
  dlina = arr[finish.x][finish.y];
  if(dlina == inf)
    negative();
  else
    all_way();
}

void Graph::all_way()
{
  kletka a;
  int i = 0, j = 0, u = 0, v = 0, shet = 1;
  itog = new kletka[dlina + 1];
  itog[0] = finish;

  Q.push(finish);

  while(shet != dlina)
  {
   i = Q.front().x;
   j = Q.front().y;
   Q.pop();

   for(int k = 0; k < 8; ++k)
    {
      u = i - dx[k];
      v = j  - dy[k];

      if(u >= 0 && u < n && v >= 0 && v < m && arr[u][v] == arr[i][j] - 1)
      {
       a.new_kletka(u, v);
       Q.push(a);
       itog[shet] = a;
       shet++;
       break;
      }
    }
  }
  itog[dlina] = start;
  result();
}

void Graph::result()
{
  cout << dlina << endl;

  for (int i = dlina; i >= 0; i--)
   cout << itog[i].x + 1 << " " << itog[i].y +1  << endl;
}

int main()
{
    int n, m, x1, y1, x2, y2;
    cin >> n >> m;
    cin >> x1 >> y1 >> x2 >> y2;
    Graph object(n, m, x1-1, y1-1, x2-1, y2-1);
    object.smejnost();
}