In this article, I'm going to introduce a general pattern named Lazy Iterator for converting recursive traversal to iterator. Let's start with a familiar example of inorder traversal of binary tree. It is straightforward to write a recursive function…

http://www.onjava.com/pub/a/onjava/2001/05/30/optimization.htmlComparing the performance of LinkedLists and ArrayLists (and Vectors) (Page last updated May 2001, Added 2001-06-18, Author Jack Shirazi, Publisher OnJava). Tips: ArrayList is faster than…

1. 引言     在红黑树--算法导论(15)中学习了红黑树的原理.本来打算自己来试着实现一下,然而在看了JDK(1.8.0)TreeMap的源码后恍然发现原来它就是利用红黑树实现的(很惭愧学了Java这么久,也写过一些小项目,也使用过TreeMap无数次,但到现在才明白它的实现原理).因此本着"不要重复造轮子"的思想,就用这篇博客来记录分析TreeMap源码的过程,也顺便瞅一瞅HashMap. 2. 继承结构 (1) 继承结构 下面是HashMap与TreeMap的继承结构: pu…

/** * An object that maps keys to values. A map cannot contain duplicate keys; * each key can map to at most one value. * * <p>This interface takes the place of the <tt>Dictionary</tt> class, which * was a totally abstract class rather t…

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another comput…

众所周知,default是java的关键字之一,使用场景是配合switch关键字用于条件分支的默认项.但自从java的jdk1.8横空出世以后,它就被赋予了另一项很酷的能力——在接口中定义非抽象方法. 众所周知,java的接口只能定义静态且不可变的常量或者公共抽象方法,不可能定义非抽象的具体方法.但自从jdk1.8横空出世以后,它就被default关键字赋予了另一项很酷的能力——在接口中定义非抽象方法.好了不废话了,看具体例子吧: 1.父接口Iterable,定义了两个default方法forE…

最近想深入的理解一下java 的工作机制,也是便于后期的面试. 1.A:HashMap和Hashtable有什么区别? Q:HashMap和Hashtable都实现了Map接口,因此很多特性非常相似.但是,他们有以下不同点:     HashMap允许键和值是null,而Hashtable不允许键或者值是null.    Hashtable是同步的,而HashMap不是.因此,HashMap更适合于单线程环境,而Hashtable适合于多线程环境.   我们再来剖析一下这个问题,如果你答些,面试…

ylbtech-Java-Class-I:java.util.Map 1.返回顶部 1.1. import java.util.HashMap; import java.util.Map; 1.2. Map newMap = new HashMap(); newMap.put("key","value"); 1.3. //请求体 Map<String, Object> requestParam = new HashMap<>(); reque…

转载:https://blog.csdn.net/hacker_zhidian/article/details/80590428 Java集合概况就三个:List.set和map list(ArrayList.Linkedlist.vector).set(Treeset.hashset).map(hashmap.hashtable.treemap) list接口: /* * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All r…

Traditional Ways of Tree Traversal This page contains examples of some “standard” traversal algorithms (ones that can be found in most textbooks). All examples perform pre-order tree traversal on a general rooted tree. “Algorithms, Data Structures an…