java certifications list

listIterator(); } public abstract ListIterator listIterator(int index);} This class uses a large number of Iterator for sequential traversal of sets. Because it cannot be randomly located, this class focuses on sequential traversal. If you want to implement a list set by yourself, it is best to inherit this abstract class, in this way, you don't have to bother yourself to implement so many methods.

A little bit of work experience may not be correct, even if it is not correct. Java list is just a container interface. Defining a list must be implemented using some implementation classes such as arraylist. Several key points for using list: ① The add () method of list ca

Java Collection of dry goods-inventory list source code analysis, dry goods inventory listPreface In the previous article, we analyzed ArrayList in detail. Today we will talk about 'arraylist. What is the difference between them? The biggest difference is that the underlying data structure is implemented differently. ArrayList is implemented by arrays (see the previous article), and LinedList is implemented

109-convert Sorted list to binary Search tree (sort list converted to binary sort tree)"leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a singly linked list where elements is sorted in ascending order, convert it to a height balanced BST.Main TopicGiven an as

109-convert Sorted list to binary Search tree (sort list converted to binary sort tree)"leetcode-Interview algorithm classic-java Implementation" "All Topics folder Index"Original QuestionGiven a singly linked list where elements is sorted in ascending order, convert it to a height balanced BST.Main TopicGiven an ascen

. Linear chain-type storage structure: Any storage unit that takes a set of addresses holds data elements in a linear table.Linked lists can also be divided into: Single linked list: Each node retains only one reference, which points to the next node of the current node, no reference to the head node, and the next reference to the tail node is null. Circular link list: A linked

Java list sorting collections. Sort () sorting list // A pojo example Class user {String name;String age;Public user (string name, string age ){This. Name = Name;This. Age = age;}Public String getage (){Return age;}Public void setage (string age ){This. Age = age;}Public String getname (){Return name;}Public void setname (string name ){This. Name = Name;}} // Spe

"092-reverse Linked List II (Reverse single link List ii)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionReverse a linked list from position m to N. Do it in-place and in One-pass.For example:Given 1->2->3->4->5->NULL , m = 2 and n = 4 ,Return 1->4->3->2->5->NULL

written.The first time I used a hash table, I think it is also drunk, but after the optimization of the time gradually 2 hash table 1 hash table.Three methods of solution are actually the same, but initially there are a lot of redundant places.Solution 1: public static Randomlistnode Copyrandomlist (Randomlistnode head) {//define hash table HashmapSolution 2: public static Randomlistnode CopyRandomList2 (Randomlistnode head) {//New two hash tables are stored in the original node and the random

JAVA linked list operation: cyclic chain list Main analysis Examples: First, single linked list cycle list Double linked list Cycle list The single linked table node and the Double

"114-flatten binary tree to Linked list (binary trees to single linked list)""leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a binary tree, flatten it to a linked list in-place.For example,Given 1 2 5 \ 3 4 6The flatte

Recently in the project with MyBatis, encountered the date format display to the Easyui problem, need to listThe core approach is as follows:[Java]View PlainCopy /** * object>> data is converted to JavaBean data according to List * @param datas * @param beanclass * @return * @throws commonexception */ Public list Throws Commonexception { //Re

To implement the POI export Excel shape as--A1 (LV1)----B1 (LV2)----B2 (LV2)------C1 (LV3)------C2 (LV3)----B3 (LV2)--A1 (LV1)I. Data fields that can be usedID (primary key), PID (parent account ID), name (name), level (current hierarchy)Two. Ideas:Define an empty list of accounts to hold an already sequenced account. Create an iterator to the parent node to isolate all of its child nodes, traverse the child nodes into the

The array is turned into a list:Method One:string[] UserID = {"AA", "BB", "CC"};listCollections.addall (UserList, UserID);Method Two:string[] UserID = {"AA", "BB", "CC"};ListAnother:arrays.aslist () returns a list of fixed sizes supported by the specified array. Therefore, do not do add, remove and other operations. List List = new ArrayList (arrays.aslist (useri

Title, the sample code is as follows:/*** 1> by number of copies---list *@paramSource *@paramHow many copies num wants to divide into *@return */ Public Staticintnum) {ListNewArraylist(); intRemaider=source.size ()%num;//(the remainder is calculated first) intNumber=source.size ()/num;//then the business intoffset=0;//Offset Amount for(inti=0;i) {ListNULL; if(remaider>0) {Value=source.sublist (I*number+offset, (i+1) *numb

","Zara","Yes","But","Row","OK","another"); linkednode"-------------------------------------------"); Dumplinkedlist (HEAD22);End Prepare System.out.println ("\n++++++++++++++++++++++++++++++++++++++++++\n");Start Test linkednode"-------------------------------------------"); linkednode/** recusive. Return head node as ascending. Would change parameters, non reentrant. */PublicStatic MergeSortedLinkedList1 (linkednodeif (A = =NULL) {return b; }if (b = =NULL) {return A; }if (Isfirstlessthansecond

. Link.insertlast (l); - } the Publiclinkq Remove () { the return This. Link.deletefirst (); the } the PublicString toString () { - return This. link.tostring (); the } the Public voiddisplay () { the System.out.println (toString ());94 } the } the Public classLinkqueuedemo { the Public Static voidMain (string[] args) {98Linkqueue queue =Newlinkqueue (); About for(inti = 0; I ) { -LINKQ l=NewLINKQ (i);101 Queue.insert (l);102 Queue.

Entity class:classUser {String name; String age; PublicUser (String name,string age) { This. name=name; This. age=Age ;} PublicString getage () {returnAge ;} Public voidsetage (String age) { This. Age =Age ;} PublicString GetName () {returnname;} Public voidsetName (String name) { This. Name =name;} }The specific comparison class, implements the comparator interface:ImportJava.util.Comparator;Importjava.util.List;Importjava.util.ArrayList;Importjava.util.Collections; Public classComparato