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. S
throw new QueueEmptyException("Underflow Exception"); return queue1.remove(); } public static void main(String[] args) { StackUsingTwoQueues stack = new StackUsingTwoQueues(); stack.push(20); stack.push(40); stack.push(70); stack.push(50); stack.push(90); stack.push(110); stack.pu...
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...
40. Implement Queue by Two Stacks/225. Implement Stack using Queues 本题难度: Medium/Easy Topic: Data Structure - stack/queue Description As the title described, you should only use two stacks to implement a queue's actions. The queue should support push(element), pop() and top() where ...
(self):""":rtype: int"""returnself.queue.popleft()deftop(self):""":rtype: int"""returnself.queue[0]defempty(self):""":rtype: bool"""returnnotself.queue# Your MyStack object will be instantiated and called as such:# obj = MyStack()# obj.push(x)# param_2 = obj.pop()# ...
myStack.pop(); // return 2 myStack.empty(); // return False Constraints: 1 <= x <= 9 At most 100 calls will be made to push, pop, top, and empty. All the calls to pop and top are valid. Follow-up: Can you implement the stack using only one queue? For questions of the ...
【LeetCode题解】232_用栈实现队列(Implement-Queue-using-Stacks) 目录 描述 解法一:在一个栈中维持所有元素的出队顺序 思路 入队(push) 出队(pop) 查看队首(peek) 是否为空(empty) Java 实现 Python 实现 解法二:一个栈入,一个栈出 思路 入队(push) 出队(pop) 查看队首(peek) 是否为空(empty) ...
我的LeetCode代码仓:https://github.com/617076674/LeetCode原题链接:https://leetcode-cn.com/problems/implement-queue-using-stacks/description/ 题目描述: 知识点:栈、队列 思路:双栈实现队列 push(x)和empty()的时间复杂度是O(1)。 pop()和peek()的 ...
LeetCode 225 Implement Stack using Queues 用队列实现栈,1、两个队列实现,始终保持一个队列为空即可2、一个队列实现栈
LeetCode "Implement Stack using Queues" Two-queue solution classStack { queue<int>q; queue<int>q0;int_top;public://Push element x onto stack.voidpush(intx) { q.push(x); _top=x; }//Removes the element on top of the stack.voidpop() {...