Learn Recursion by Solving the Tower of Hanoi Puzzle - Step 40

Python
1

Tell us what’s happening:

  1. You should nest your print() and make_allowed_move() calls inside an if statement to execute when n is odd.
    what should i change in my code?

Your code so far

NUMBER_OF_DISKS = 4
number_of_moves = 2**NUMBER_OF_DISKS - 1
rods = {
    'A': list(range(NUMBER_OF_DISKS, 0, -1)),
    'B': [],
    'C': []
}

def make_allowed_move(rod1, rod2):    
    forward = False
    if not rods[rod2]:
        forward = True
    elif rods[rod1] and rods[rod1][-1] < rods[rod2][-1]:
        forward = True
                      
    if forward:
        print(f'Moving disk {rods[rod1][-1]} from {rod1} to {rod2}')
        rods[rod2].append(rods[rod1].pop())
    else:
        print(f'Moving disk {rods[rod2][-1]} from {rod2} to {rod1}')
        rods[rod1].append(rods[rod2].pop())
    
    # display our progress
    print(rods, '\n')

def move(n, source, auxiliary, target):
    # display starting configuration
    print(rods, '\n')
    for i in range(number_of_moves):
        remainder = (i + 1) % 3
        if remainder == 1:
            if n % 2 != 0:
                print(f'Move {i + 1} allowed between {source} and {target}')
                make_allowed_move(source, target)

# User Editable Region

            else:
                print(f'Move {i + 1} allowed between {source} and {auxiliary}')
                make_allowed_move(source, auxiliary)            

        elif remainder == 2:
            if n % 2 != 0:
                print(f'Move {i + 1} allowed between {source} and {auxiliary}')
               #make_allowed_move(source, auxiliary)

# User Editable Region

        elif remainder == 0:
            print(f'Move {i + 1} allowed between {auxiliary} and {target}')
            make_allowed_move(auxiliary, target)
           
# initiate call from source A to target C with auxiliary B
move(NUMBER_OF_DISKS, 'A', 'B', 'C')

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Challenge Information:

Learn Recursion by Solving the Tower of Hanoi Puzzle - Step 40

2

Hi there and welcome to our community!

Now you need to do the same with your elif statement: put the print() and make_allowed_move() calls inside an if statement to execute when n is odd.

Also, turn the # make_allowed_move(source, auxiliary) comment into code.

First, you need to nest another if statement inside the elif statement, as you did above with the if remainder == 1: statement.

Then you need to uncomment the make_allowed_move() call which is in the elif remainder == 2: statement.

3

Thank you ! That worked