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 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. Notes: You must useonlystandard operatio...
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. Notes: You must use only standard oper...
如果stack 2 为空,则把 stack 1的元素全部移动到 stack 2,并返回栈顶元素 pop() 类似于peek,但是在返回的时候是移除操作并返回该元素。 1 读题 LeetCode 232E 用栈实现队列 Implement Queue using Stacks 2 Python 解题 正如咱们前面那个问题,list 既可以实现栈,还能实现列表,所以咱这题的代码,和那个队列模...
class MyQueue { Stack<Integer> stack; /** Initialize your data structure here. */ public MyQueue() { stack = new Stack<>(); } /** Push element x to the back of queue. */ public void push(int x) { stack.push(x); } /** Removes the element from in front of queue and retur...
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...
In this tutorial, we’re going to implement a stack data structure using two queues. 2. Stack and Queue Basics Before proceeding to the algorithm, let’s first take a glance at these two data structures. 2.1. Stack In a stack, we add elements in LIFO (Last In, First Out) order.This...
A classic interview question.This linkhas a nice explanation of the idea using two stacks and its amortized time complexity. I use the same idea in my code, which is as follows. 1classQueue {2public:3//Push element x to the back of queue.4voidpush(intx) {5stack1.push(x);6}78//...
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...
shiftStack();if(!_old.empty())return_old.top();return0; }//Return whether the queue is empty.boolempty(void) {return_old.empty() &&_new.empty(); }private: stack<int>_old, _new; }; 用栈来实现队列[LeetCode] Implement Queue using Stacks,如需转载请自行联系原博主。