def update_location(i,j,location):
    if i == len(location) - 1 and j == len(location) - 1:
    # if i and j == last row and column in location then do nothing
        pass

    elif j == len(location) - 1:  # if j == last index, update next row index 0

        if location[i + 1][0][1] == matrix[i][j + 1]:  # [i+1][0] == next row index 0
            location[i + 1][0][0] = 1
        elif location[i + 1][0][1] == matrix[i][-1 - j]:
            location[i + 1][0][0] = 2
        elif location[i + 1][0][1] == matrix[-1 - i][j + 1]:
            location[i + 1][0][0] = 3
        elif location[i + 1][0][1] == matrix[-1 - i][-1 - j]:
            location[i + 1][0][0] = 4
    else:  # update next j+1
        print('******************')
        print('max = '+ str(location[i][j + 1][1]))
        print(matrix[i][j + 1],matrix[i][-1 - (j+1)],matrix[-1 - i][j + 1],matrix[-1 - i][-1 - (j+1)])
        if location[i][j + 1][1] == matrix[i][j + 1]:
            print('update to 1')
            # if j exceed len(location), go to next i and start j = 0 again
            location[i][j + 1][0] = 1
        elif location[i][j + 1][1] == matrix[i][-1 - (j+1)]: #need to use -(j+1)
            print('update to 2')
            location[i][j + 1][0] = 2
        elif location[i][j + 1][1] == matrix[-1 - i][j + 1]:
            print('choose to 3')
            location[i][j + 1][0] = 3

        elif location[i][j + 1][1] == matrix[-1 - i][-1 - (j+1)]:
            print('update to 4')
            location[i][j + 1][0] = 4
    return location

    #6x6 wrong at 1,1 and 2,1 26 should be 29 and 20 ->23
    #step24 num 20 doing Q4 then update wrong location
    # before step 24 doing Q4
    #step25 num 26 doing Q4 then update wrong location
    # before step 25 doing Q4

    #เข้าเงื่อนไข else แต่ max ไม่ตรงกับ ค่าใน matrix เลยดักไม่ได้

# if max in q1 -> no move
# if max in q2 -> cur box down, max box down, max box left , max box up
# if max in q3 -> cur box right, max box right, max box up, max box left
# if max in q4 -> cur box right, max box up, max box left