225. 用队列实现栈 Implement Stack using Queues难度:Easy | 简单相关知识点:栈、设计题目链接:https://leetcode-cn.com/problems/implement-stack-using-queues/官方题解:https://leetcode-cn.com/problems/implement-stack-using-queues/solu
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;/** * ...
return queue1.empty() && queue2.empty(); } }; 其他解法: 【两个队列】用两个队列myStack,temp实现一个栈。push时把新元素添加到myStack的队尾。pop时把myStack中除最后一个元素外逐个添加到myStack中,然后pop掉myStack中的最后一个元素,然后注意记得myStack和temp,以保证我们添加元素时始终向temp中添加...
## 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## ...
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...
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 re...
class MyStack{public:/** Initialize your data structure here. */MyStack(){}/** Push element x onto stack. */voidpush(intx){q.push(x);top_value=x;}/** Removes the element on top of the stack and returns that element. */intpop(){queue<int>temp;while(q.size()!=1){temp.push...
You may assume that all operations are valid (for example, no pop or top operations will be called on an empty stack). 解题思路: 方法一(两个队列): 队列先进后出,栈后进先出。 用队列实现栈,可以用两个队列完成题解: 出栈:入栈时用 queue1 来存入节点;出栈时queue1 内节点顺序出队列并入队列到...
queue<int> q1; public: /** Initialize your data structure here. */ MyStack() { } /** Push element x onto stack. */ void push(int x) { queue<int> tmp; while(!q1.empty()){ tmp.push(q1.front()); q1.pop(); } q1.push(x); ...
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...