Implement the following operations of a stack using queues. push(x) -- Push element x onto stack. pop() -- Removes the element on top of the stack. top() -- Get the top element. empty() -- Return whether the stack is empty. Notes: You must use only standard operations of a queu...
https://leetcode.com/problems/implement-stack-using-queues/ 还有种方法,就是利用同一个队列,知道队列长度前提下,把内容从头到尾,再向尾部依次重推一下。 package com.company; import java.util.Deque; import java.util.LinkedList; import java.util.Queue;classSolution { Queue[] queues;intcur; Solution(...
一、Implement Stack using QueuesImplement the following operations of a stack using queues.push(x) -- Push element x onto stack.pop() -- Removes the ele
Implement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack (push, top, pop, and empty). Implement the MyStack class: void push(int x) Pushes element x to the top of the stack. int pop() Removes the el...
// Push element x onto stack. public void push(int x) { queues[cur].offer(x); } // Removes the element on top of the stack. public void pop() { change(true); } // Get the top element. public int top() { return change(false); ...
Implement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack (push, top, pop, and empty). Implement the MyStack class: void push(int x) Pushes element x to the top of the stack. ...
Implement Stack using Queues import java.util.*;classMyStack{Queue<Integer>q1;Queue<Integer>q2;/** Initialize your data structure here. */publicMyStack(){q1=newLinkedList<Integer>();q2=newLinkedList<Integer>();}/** Push element x onto stack. */publicvoidpush(intx){q1.offer(x);}/** ...
/** Push element x onto stack. */ public void push(int x) { if(queue1.isEmpty()){ queue2.offer(x); }else{ queue1.offer(x); } } /** Removes the element on top of the stack and returns that element. */ public int pop() { ...
https://leetcode-cn.com/problems/implement-stack-using-queues/ 思路 首先演示push()操作; 将元素依次进入队1,进入时用top元素保存当前进入的元素; 如下图: push操作的演示 然后演示pop()操作; 先将除队1中的最后一个元素出队并进入队2,入队2时用top存储入队元素; 再将队列1和队列2进行互换即可。 如下...
Leetcode 225 Implement Stack using Queues 使用队列实现栈 题目要求的是栈的内部存储数据结构为队列。 主要需要调整push操作,需要使得后面进入的数据在队列的头部。 解决方法可以使用一个临时队列,在push元素时,利用临时队列调换次序,先将新元素push到临时队列,再将原队列内容全部push到临时队列,最后将临时队列里面的元...