stack1(in): is the only stack to store new elements when adding a new element into the queue stack2(out): is the only stack to pop old element out of the queue. when stack2 is empty, we move all data from stack1(in) to stack2(out) if any **/publicclassQueueUseStack {privateD...
Implement Queue by Two Stacks Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front element. empty() -- Return whether the queue is empty. 1classMy...
http://www.lintcode.com/en/problem/implement-queue-by-two-stacks/ 【题目解析】 用两个Stack来实现一个Queue,可以考虑到push()时,几乎与Queue中的offer()一样,都是加在末尾,区别是当Stack pop()时,取出的是最近加入(newest)的元素,而Queue用poll()则是将最老(oldest)的元素取出。使用2个Stack,可以将s...
Implement a first in first out (FIFO) queue using only two stacks. The implemented queue should support all the functions of a normal queue (push, peek, pop, and empty). Implement the MyQueue class: void push(int x) Pushes element x to the back of the queue. int pop() Removes the...
class QueueTwoStacks(object): # Implement the enqueue and dequeue methods def enqueue(self, item): pass def dequeue(self): pass # Tests class Test(unittest.TestCase): def test_basic_queue_operations(self): queue = QueueTwoStacks() queue.enqueue(1) queue.enqueue(2) queue.enqueue(3) actual...
To construct a stack using two queues (q1,q2), we need to simulate the stack operations by using queue operations: push(Eelement) ifq1is empty,enqueueEtoq1 ifq1is not empty,enqueueall elements fromq1toq2, thenenqueueEtoq1, andenqueueall elements fromq2back toq1 ...
Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front element. empty() -- Return whether the queue is empty. ...
题目 大意是使用queue队列(仅用标准操作)来实现stack的操作。 我的代码 主要思路:使用了双端队列,但默认屏蔽一些功能。使用了popleft() 和append()来实现。 优秀代码(使用类似rotate()方法)... 225. Implement Stack using Queues Implement the following operations of a stack using queues. push(x) -- Push...
第六题:LeetCode-232-Implement Queue using Stacks Subject: Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front elemen... ...
As the title described, you should only use two stacks to implement a queue's actions. The queue should supportpush(element),pop()andtop()where pop is pop the first(a.k.a front) element in the queue. Both pop and top methods should return the value of first element. ...