题目: 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. empty() -- Return whether the queue is empty. Notes:
在了解WeakReference之前,先给出一段简单的代码: public class WeakReferenceTest {public static void main(String[] args) throws Exception {Object o = new Object();// 默认的构造函数,会使用ReferenceQueue.NULL 作为queueWeakReference<Object> wr = new WeakReference<Object>(o);Sy
在前面几篇博文中曾经提到链表(list).队列(queue)和(stack),为了更加系统化,这里统一介绍着三种数据结构及相应实现. 1)链表 首先回想一下基本的数据类型,当需要存储多个相同类型的数据时,优先使用数组.数组可以通过下标直接访问(即随机访问),正是由于这个优点,数组无法动态添加或删除其中的元素,而链表弥补了这种缺陷.首先看一下C风格的单链表节点声明: // single list node define typedef struct __ListNode { int val; st
std::queue template <class T, class Container = deque<T> > class queue; FIFO queue queues are a type of container adaptor, specifically designed to operate in a FIFO context (first-in first-out), where elements are inserted into one end of the
Suppose you have a random list of people standing in a queue. Each person is described by a pair of integers(h, k), where h is the height of the person and k is the number of people in front of this person who have a height greater than or equal to h
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. empty() -- Return whether the queue is empty. Notes: You