Python mirror queue and reverse queue 1. Write a function, mirror_queue(q) , whi

Question

Python mirror queue and reverse queue

1.

Write a function, mirror_queue(q), which takes a Queue, q, as a parameter and modifies the queue so that the queue items appear in their original order followed by a copy of the queue items in reverse order. You must make use of a stack to help you to solve this problem.

The implementations of both the Stack and Queue ADTs are provided to you. You can simply use: push(), pop(), is_empty() as well as enqueue() and dequeue() as necessary in your function definition.

However, you will need to use the following statement to create a Stack (in this question)

Similarly, you will need to use the following statement to create a Queue (in this question)

For example:

2.

Write a function, reverse_queue(q), which takes a Queue, q, as a parameter and modifies the queue so that the elements in the queue are rearranged into reverse order. You must make use of a stack to help you in reversing the elements in the queue.     

The implementations of both the Stack and Queue ADTs are provided to you. You can simply use: push(), pop(), is_empty() as well as enqueue() and dequeue() as necessary in your function definition.

However, you will need to use the following statement to create a Stack (in this question)

Similarly, you will need to use the following statement to create a Queue (in this question)

For example:

  q1 = my_queue_module.Queue()  q1.enqueue(1)  q1.enqueue(2)  q1.enqueue(3)  mirror_queue(q1)  print(q1)  

  Queue: [1, 2, 3, 3, 2, 1]

  q1 = my_queue_module.Queue()  mirror_queue(q1)  print(q1)

  Queue: []

Explanation / Answer

def mirror_queue(q):
   s = my_stack_module.Stack()
   q1 = my_queue_module.Queue()
   while (!q.is_empty()):
        a = q.dequeue()
        q1.enqueue(a)
        s.push(a)
   while !q1.is_empty():
        a = q1.dequeue()
        q.enqueue(a)
       
   while !s.is_empty():
        a = s.pop()
        q.enqueue(a)
   return q

def reverse_queue(q):
   s = my_stack_module.Stack()
   while !q.is_empty():
        a = q.dequeue()
        s.push(a)
       
   while !s.is_empty():
        a = s.pop()
        q.enqueue(a)
   return q

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