class QueueUsingStack:
'''
Implementing Queue using two stacks
We implement only enqueue and dequeue methods
'''
def __init__(self):
self.a_stack = Stack(20)
self.b_stack = Stack(20)
def enqueue(self, x):
self.a_stack.push(x)
print("Enqueueing element: {}\n".format(x))
print("A Stack: ", end="")
self.a_stack.print()
print("B Stack: ", end="")
self.b_stack.print()
print("---------------------------------------------")
def dequeue(self):
if not self.b_stack.isEmpty():
element = self.b_stack.pop()
else:
while (self.a_stack.top != 0):
x = self.a_stack.pop()
self.b_stack.push(x)
element = self.a_stack.pop()
print("Dequeued element: {}\n".format(element))
print("A Stack: ", end="")
self.a_stack.print()
print("B Stack: ", end="")
self.b_stack.print()
print("---------------------------------------------")
return element
