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Queue2Stacks.py
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Queue2Stacks.py
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# -*- coding: utf-8 -*-
"""
Created on Wed Aug 1 11:32:57 2018
@author: sanooj
"""
from Stack import Stack
"""
Implemnet a Queue FIFO structure
"""
class Queue2Stacks(object):
# stacks
def __init__(self):
self.stack1 = Stack()
self.stack2 = Stack()
def enqueue(self, element):
# clear stack2
#self.stack2.items.clear()
# copy to stack 2
# order reversed
size_stack1 = \
self.stack1.size()
for member in range(0,size_stack1):
peeked = \
self.stack1.pop()
self.stack2.push(peeked)
# insert to stack 2
# gets added to last index
self.stack2.push(element)
print("enqueue")
print(self.stack1.items)
print(self.stack2.items)
def dequeue(self):
# clear stack 1
# self.stack1.items.clear()
size_stack2 = \
self.stack2.size()
# copy stack 2 to stack 1
for member in range(0,size_stack2):
peeked = \
self.stack2.pop()
self.stack1.push(peeked)
# pop from stack 2
# pops last index
popped = \
self.stack1.pop()
print("dequeue")
print(self.stack1.items)
print(self.stack2.items)
return popped
s = Queue2Stacks()
#print(s.is_empty())
s.enqueue("one")
s.enqueue("two")
s.enqueue("three")
#print(s.items)
#print(s.peek())
#print(s.size())
#print(s.is_empty())
print(s.dequeue()) # "one"
s.enqueue("four")
print(s.dequeue()) # "two"
print(s.dequeue()) # "three"
s.enqueue("five")
print(s.dequeue()) # "four"
#print(s.size())
#print(s.peek())
def q():
print("Q()")
from Queue import Queue
s = Queue()
#print(s.is_empty())
s.enqueue("one")
s.enqueue("two")
s.enqueue("three")
print(s.items)
#print(s.peek())
#print(s.size())
#print(s.is_empty())
print(s.dequeue()) # "one"
print(s.items)
s.enqueue("four")
print(s.items)
print(s.dequeue()) # "two"
print(s.items)
print(s.dequeue()) # "three"
print(s.items)
s.enqueue("five")
print(s.items)
print(s.dequeue()) # "four"
print(s.items)
q()
def test_Q2S():
q = Queue2Stacks()
for i in range(5):
q.enqueue(i)
for i in range(5):
print(q.dequeue())
test_Q2S()
class Queue2StacksP(Queue2Stacks):
def __init__(self):
self.instack = []
self.outstack = []
# @override
def enqueue(self,element):
self.instack.append(element)
# @override
def dequeue(self):
if not self.outstack:
while self.instack:
self.outstack.append(
self.instack.pop()
)
return self.outstack.pop()
def test_Q2SP():
q = Queue2StacksP()
for i in range(5):
q.enqueue(i)
for i in range(5):
print(q.dequeue())
test_Q2SP()