【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)
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## Removes the top element and returnifself.l1:whilelen(self.l1)>1:self.l2.append(...
Queue<Integer> q;publicMyStack(){// int size():获取队列长度;//boolean add(E)/boolean offer(E):添加元素到队尾;//E remove()/E poll():获取队首元素并从队列中删除;//E element()/E peek():获取队首元素但并不从队列中删除。q =newLinkedList<>(); }publicvoidpush(intx){ q.add(x);fo...
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 ...
class Stack { public: // Push element x onto stack. void push(int x) { if(q1.empty()&&q2.empty()) q1.push(x); else if(!q1.empty()) q1.push(x); else q2.push(x); } // Removes the element on top of the stack. void pop() { if(!q1.empty()) { while(q1.size()!=1...
leetcode225 implement stack using queues 题目要求 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....
* @return Integer */ function top() { return end($this->q1); } /** * Returns whether the stack is empty. * @return Boolean */ function empty() { return empty($this->q1) ? true : false; } } 解法2:单队列 用一个队列,将新元素压入队尾,然后将队首元素弹出,放到新元素后面,直到...
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, andempty). Implement theMyStackclass: void push(int x)Pushes element x to the top of the stack. ...
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...
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.