Transpose array without any other array in java

import java.io.*;
class transpose_1array
  {
      public void transpose()throws IOException
      {
          BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
          int i,j,t=0;
          System.out.println("Enter the size of the array");
          int n=Integer.parseInt(br.readLine());
          int arr[][]=new int[n][n];
          for(i=0;i<n;i++)
          {
              for(j=0;j<n;j++)
              {
                  System.out.println("Enter element at "+i+","+j);
                  arr[i][j]=Integer.parseInt(br.readLine());
                }
            }
           for(i=0;i<n;i++)
           {
               for(j=0;j<i;j++)
               {
                   t=arr[i][j];
                   arr[i][j]=arr[j][i];
                   arr[j][i]=t;
                }
            }
            for(i=0;i<n;i++)
            {
                for(j=0;j<n;j++)
                System.out.print(arr[i][j] + "  ");
                 System.out.println();
            }
          
        }
    }