Implement a Queue using Two Stacks

queue-as-two-stacks.py

"""
Stack and Queue being implemented with Python List.

Both structures follow the design below:
  Bottom -> [...] -> Top.
"""

def dequeue(array: list) -> int:
  return array.pop()


def empty_one_fill_the_other(stack1: list, stack2:list):
  while len(stack1) > 0:
    value = stack1.pop()
    stack2.append(value)
  
  return stack2

def main():
  stck_one = [1,2,3]
  stck_two = []
  
  queue = empty_one_fill_the_other(stck_one, stck_two)
  # After this, we should re do the same step in the other
  # direction, to keep the initial state intact.
  
  # Should be equal to 1.
  print(dequeue(queue))


if __name__ == "__main__":
  main()