coding for interviews #20

gistfile1.py

class Queue(object):
    def __init__(self):
        self.stack1 = Stack()
        self.stack2 = Stack()
        
    def enqueue(self,p):
        self.stack1.push(p)
        
    def dequeue(self):
        #pop off all in 1 onto 2
        while not self.stack1.isEmpty():
            self.stack2.push(self.stack1.pop())
            
        #pop off stack 1
        returnValue = self.stack2.pop()
        
        #re pop off all in 2 onto 1
        while not self.stack2.isEmpty():
            self.stack1.push(self.stack2.pop())
            
        return returnValue