Daily Coding Problem: Problem #1

problem1.py

"""
This problem was asked by Google.

Given a stack of N elements, interleave the first half of the stack with the second half reversed using only one other queue. This should be done in-place.

Recall that you can only push or pop from a stack, and enqueue or dequeue from a queue.

For example, if the stack is [1, 2, 3, 4, 5], it should become [1, 5, 2, 4, 3]. If the stack is [1, 2, 3, 4], it should become [1, 4, 2, 3].

Hint: Try working backwords from the end state.

https://dailycodingproblem.com/
"""

def queue_interleave(stack):
  queue = []
  while len(stack) > 0:
    queue.append(stack.pop(0))
    if len(stack) > 0:
      queue.append(stack.pop())
  return queue
  
if __name__ == '__main__':
  # Read input, numbers separated by commas
  stack = [int(n) for n in input().split(',')]
  print(queue_interleave(stack))

Instead why can't we just create classes for both Stack and Queue along with its FILO and FIFO properties with a few of the necessary properties like "push()" and "pop()" for Stack and "enqueue()" and "dequeue()" for Queue. And the a few helper classes to do the above program in place(Consisting of Stack and Queue only as per the question).

https://github.com/Nabushan/Interleave_Stack_using_Queue/blob/d1f8c4bdbc73846bcae976f773ee894ebc2b93ef/code.py#L11

Hope so it helps if there's any changes, correction or Suggestion feel free to Comment.

Thanks.