empty() -- Return whether the stack is empty. 我的解法一,python使用collections.deque() classStack(object): def __init__(self):"""initialize your data structure here."""self.queue =collections.deque() def push(self, x):""":type x:int:rtype: nothing"""self.queue.append(x) def pop...
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. Example: MyStack stack =newMyStack(); stack.push(1)...
deque() def push(self, x): self.data.append(x) def peek(self): return self.data[0] def pop(self): return self.data.popleft() def size(self): return len(self.data) def empty(self): return len(self.data) == 0 class Stack: # initialize your data structure here...
So, while it’s possible to build a thread-safe Python stack using adeque, doing so exposes yourself to someone misusing it in the future and causing race conditions. Okay, if you’re threading, you can’t uselistfor a stack and you probably don’t want to usedequefor a stack, so ...
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...
python代码: classMyStack(object):def__init__(self):""" Initialize your data structure here. """self.stack=[]defpush(self,x):""" Push element x onto stack. :type x: int :rtype: void """self.stack.append(x)defpop(self):""" ...
225. 用队列实现栈 - 请你仅使用两个队列实现一个后入先出(LIFO)的栈,并支持普通栈的全部四种操作(push、top、pop 和 empty)。 实现 MyStack 类: * void push(int x) 将元素 x 压入栈顶。 * int pop() 移除并返回栈顶元素。 * int top() 返回栈顶元素。 * boole
Accessing Random Items in a deque Building Efficient Queues With deque Exploring Other Features of deque Limiting the Maximum Number of Items: maxlen Rotating the Items: .rotate() Adding Several Items at Once: .extendleft() Using Sequence-Like Features of deque Putting Python’s deque Into Action...
要实现队列,请使用collections.deque设计为具有快速追加和从两端弹出的队列。例如 【Leetcode 225】 Implement Stack using Queues - EASY : push:O(n) pop:O(1) top:O(1) empty:O(1) 空间复杂度: O(1) 思路反思 首先有一点,我们上面所使用的方法是认为队列1和队列2有差别,永远往队列1中插入数据,用...
queue = deque() We create an empty queue using the `deque()` constructor from the `deque` class. This creates an empty queue object that we will use to store the elements. 3. Start the menu-driven loop: while True: print("Menu:") print("1. Add element to the queue") print("2...