SPIRAL ARRAY IN CLOCKWISE

InterviewBit spiral array problem solution in java

specification:-
Given a matrix of m * n elements (m rows, n columns), return all elements of the matrix in spiral order.
Example:-
Input
[
    [ 1, 2, 3 ],
    [ 4, 5, 6 ],
    [ 7, 8, 9 ]
]

output
[1, 2, 3, 6, 9, 8, 7, 4, 5]

Explanation-

        top->  1 2 3 4
               6 8 9 6
        btm->  2 4 3 5
               ^     ^
               |     |
               lft   rht

########################JAVA CODE######################################################################

public class Solution {
    // DO NOT MODIFY THE ARGUMENTS WITH "final" PREFIX. IT IS READ ONLY
    public int[] spiralOrder(final int[][] mat) {

        int k=0;
        int m=mat.length;
        int n=mat[0].length;
        if(m==1 && n==1)
           return mat[0];
        int arr[]=new int[m*n];
         int top=0,btm=m-1,lft=0,rht=n-1,dir=0;
       while(top<=btm && lft<=rht)
                {
                  if (dir==0) //Move left to right 
                   {
                   for(int i=top;i<=rht;i++)
                    {
                     arr[k++]=mat[top][i];
                     }
                     top=top+1;
                     dir=1;
                     }
                    else if(dir==1)//Move top to bottom
                     {
                       for(int i=top;i<=btm;i++)
                        {
                          arr[k++]=mat[i][rht];
                         }
                         rht=rht-1;
                         dir=2;
                         
                       }
                     else if(dir==2)//move right to left
                       {
                        for(int i=rht;i>=lft;i--)
                        {
                         arr[k++]=mat[btm][i];
                         }
                         btm=btm-1;
                         dir=3;
                         
                        }
                        else if(dir==3) ///move bottom to top
                        {
                         for(int i=btm;i>=top;i--)
                         {
                         arr[k++]=mat[i][lft];
                         }
                         lft=lft+1;
                         dir=0;
                        }
                   }
        return arr;
    }
}