Keypad - DP

#include <bits/stdc++.h> 
int helper(int x , int y , int n , vector < vector <int> > &keypad ,  vector < vector < vector <int> > >  &dp)
{
    int mod = 1e9 + 7 ; 
    if(n == 0)
    {
        //cout << "bc" << x << y<< endl;
        return 1 ; 
    }
  //  cout << "i" << " " <<  x << y << endl ;
    int a[5] = {-1 , +1 , 0 , 0 , 0 } ;
    int b[5] = {0 , 0 , +1 , -1 , 0} ;
    int s = 0 ; 
     if(dp[x][y][n] != -1)
     {
         return dp[x][y][n] ;
     }
    for(int i = 0 ; i  <  5; i++)
    {
       int xcor = x + a[i] ;
       int ycor = y + b[i] ;
       if(xcor < 4 && ycor < 3 &&  xcor >= 0 && ycor >= 0 && keypad[xcor][ycor] != 10 && keypad[xcor][ycor] != 11)
       {
           // cout << xcor << ycor << s << endl ;
           s =( s  + helper(xcor ,  ycor , n - 1 , keypad,dp) ) % mod  ;
          
       } 
    
    }
    return dp[x][y][n] = s; 
}
int generateNumbers(int n)
{
    
    vector< vector <int> > keypad{
      {1, 2, 3}, {4, 5, 6}, {7, 8, 9}, { 10, 0, 11 }
    } ;
     vector < vector < vector <int> > >  dp(4 , vector <vector <int> > (3 , vector <int> (n + 1 , -1)) ) ; 
     int mod = 1e9 + 7 ; 
    int c = 0 ; 
    for(int i = 0 ; i < 3; i++)
    {
       for(int j = 0 ; j < 3 ; j++)
       {
           
          c =  (c + helper(i , j ,n - 1 , keypad , dp)) % mod ;
         // cout << i << j << c << endl ; 
       }
       //cout << i << j << c << endl ; 

    }
     c =  (c + helper(3 , 1 ,n - 1 , keypad , dp )) % mod ;
      // c = helper(2 , 2 , n - 1 , keypad) ;
    return c ; 

    // Write your code here.
}