importjava.util.NoSuchElementException;importjava.util.LinkedList;importjava.util.Queue;classMyStack{/** * The main queue using to store all the elements in the stack */privateQueue<Integer> q1;/** * The auxiliary queue using to implement `pop` operation */privateQueue<Integer> q2;/** * ...
queue1.push(tmp); } }else{ queue2.push(x); while(!queue1.empty()){ inttmp = queue1.front(); queue1.pop(); queue2.push(tmp); } } } // Removes the element on top of the stack. voidpop() { if(!queue1.empty()) queue1.pop(); if(!queue2.empty()) queue2.pop(); } ...
## LeetCode 232classMyQueue:def__init__(self):self.l1=[]## queue1 = l1self.l2=[]## queue2 = l2defpush(self,x:int)->None:## Push x onto stackself.l1.append(x)## The right of the list = the top of the stack = the back of the queuedefpop(self)->int:## pop 抽取## ...
仅使用两个队列(queue)实现一个后进先出(last-in-frist-out)(LIFO)的栈(stack)。你实现的栈需要满足常规栈的操作。(push、top、pop、empty)。 implement the MyStack class: void push(int x) Pushes element x to the top of the stack. int pop() Removes the element on the top of the stack and...
Implement Queue using Stacks 解题报告:这个就是考虑Queue 和 Stack的输入输出数据结构的不同, 我看LeetCode上还有大神直接用peek peek就完事了的, 我这个就是比较笨的方法。 首先确定要有两个stack存数据, 我是设定一个stack 存有所有的数据, 基本上这个stack 就是个queue 。 再回来考虑queue和stack 的区别, ...
empty() -- Return whether the stack is empty. Notes: You must use only standard operations of a queue -- which means only push to back , peek/pop from front , size , and is empty Depending on your language, queue may not be supported natively. You may simulate a queue by using a...
Depending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as long as you use only standard operations of a stack. You may assume that all operations are valid (for example, no pop or peek operations will be...
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...
Depending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as long as you use only standard operations of a stack. You may assume that all operations are valid (for example, no pop or peek operations will be...