public static void changeArray(int[][] original, int[][] copy ){

    for (int i = 0; i < original.length; i++)
      for (int j = 0; j < original[0].length; j++)
      original[i][j] = copy[i][j];


  }

  public static void horizontalFlip(int[][] a){
    int[][] replacement = new int[a.length][a[0].length];

    for (int i = (a.length - 1), x = 0; i > -1; i--, x++)
      for (int j = 0, y = 0; j < a[0].length; j++, y++)
      replacement[x][y] = a[i][j];
      changeArray(a, replacement);



  }
  // [4][1] [1][4]
  // [3][2] [2][3]

  public static void verticalFlip(int[][] b){
    int[][] replacement = new int[b.length][b[0].length];

    for (int i = 0, x = 0; i < b.length; i++, x++)
      for (int j = (b[0].length -1), y = 0; j > -1; j--, y++)
      replacement[x][y] = b[i][j];
      changeArray(b, replacement);


  }