curriculum/challenges/english/blocks/learn-recursion-by-solving-the-tower-of-hanoi-puzzle/64de7be06eb689161dd63cf0.md
The conditionals you wrote previously are only valid for odd numbers of disks.
Add a nested if to execute when n is odd, and add one indent level to your print() and make_allowed_move() calls.
You should nest an if statement to execute when n is odd. Don't forget to indent your print() and make_allowed_move() calls.
({ test: () => assert.match(code, /if\s+n\s*%\s*2\s*(!=\s*0|==\s*1)\s*:\s+print.*\s+make_allowed_move\(.*\)/) })
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
--fcc-editable-region--
if remainder == 1:
print(f'Move {i + 1} allowed between {source} and {target}')
make_allowed_move(source, target)
--fcc-editable-region--
elif remainder == 2:
print(f'Move {i + 1} allowed between {source} and {auxiliary}')
make_allowed_move(source, auxiliary)
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')