Java数据结构--HashTable(拉链法)

双向节点

/*** Created by root on 16-3-6.*/
public class Node<E> {public E data;public Node prev;public Node next;public Node(E target,Node prev,Node next){//链接两个孤立节点data=target;this.prev=prev;this.next=next;}public Node(){this(null,null,null);}public Node(E target){this(target,null,null);}
}

双向链表用于存储数据单元

/*** Created by root on 16-3-6.*/
public class MyLinkedList<E> {private Node beginMaker;private Node endMaker;private int size;   //lengthpublic boolean isEmpty(){return beginMaker.next==endMaker;}public MyLinkedList() {  //ConstructorbeginMaker = new Node();endMaker = new Node(null, beginMaker, null);//链接beginMaker和endMakerbeginMaker.next=endMaker;size = 0;}public MyLinkedList(int thatSize, E target) {  //Constructorthis();size = thatSize;for (int i = 0; i < size; i++) {this.add(target);}}public void add(E target) {Node node = new Node(target, endMaker.prev, endMaker);//增加一个节点 要4步node.prev.next = node;endMaker.prev = node;size++;}public boolean contains(E target) {//双向搜索Node node = findNode(target);if (node != null) {return true;} else {return false;}}public boolean remove(E target) { //deleteNode node = findNode(target);if (node != null) {node.prev.next = node.next;//把前节点和后节点链接node.next.prev = node.prev;size--;return true;}return false;}private Node findNode(E target) {//双向搜索Node node1 = beginMaker.next;Node node2 = endMaker.prev;if(isEmpty())return null;for (int i = 0; i <= size / 2; i++) {if (node1.data.equals(target)) {return node1;} else if (node2.data.equals(target)) {return node2;} else {node1 = node1.next;node2 = node2.prev;}}return null;}public Node getNode(int index) {//根据Index和 size/2 分类搜索if (index >= size) {throw new IndexOutOfBoundsException();} else if (index < size / 2) {Node node = beginMaker.next;for (int i = 0; i < index; i++) {node = node.next;}return node;} else {Node node = endMaker.prev;for (int i = size - 1; i > index; i--) {node = node.prev;}return node;}}}

HashTable List 用于存放双向链表构成一个十字链表

/*** Created by root on 16-3-6.*/
public class HashTableList {public static class hNode {MyLinkedList data;hNode prev;hNode next;public hNode(MyLinkedList list, hNode prev, hNode next) {data = list;this.prev = prev;this.next = next;}}public hNode beginMaker;public hNode endMaker;public int size;public HashTableList() {beginMaker = new hNode(null, null, null);endMaker = new hNode(null, beginMaker, null);size = 0;}public HashTableList(int size) {this();for (int i = 0; i < size; i++) {this.add(new MyLinkedList());}}public void add(MyLinkedList target) {hNode node = new hNode(target, endMaker.prev, endMaker);node.prev.next = node;endMaker.prev = node;size++;}public hNode gethNode(int index) {//根据Index和 size/2 分类搜索if (index >= size) {throw new IndexOutOfBoundsException();} else if (index < size / 2) {hNode node = beginMaker.next;for (int i = 0; i < index; i++) {node = node.next;}return node;} else {hNode node = endMaker.prev;for (int i = size - 1; i > index; i--) {node = node.prev;}return node;}}}

HashTable 用于增加和删除以及查找

/*** Created by root on 16-3-6.*/
public class HashTable<E> {HashTableList list;int size;public HashTable(int size) {list = new HashTableList(size);this.size = size;}public void insert(E target) {int hashVal = myHash(target);MyLinkedList myLinkedList = list.gethNode(hashVal).data;if (!myLinkedList.contains(target)) {myLinkedList.add(target);}}public boolean remove(E target) {int hashVal = myHash(target);MyLinkedList myLinkedList = list.gethNode(hashVal).data;return myLinkedList.remove(target);}public int myHash(E target) {int hashVal = target.hashCode();hashVal %= size;if (hashVal < 0) {hashVal += size;}return hashVal;}public int contains(E target) {int hashVal = myHash(target);MyLinkedList myLinkedList = list.gethNode(hashVal).data;if (myLinkedList.contains(target)) {return hashVal;} else {return -1;}}
}

测试类

/*** Created by root on 16-3-6.*/
public class Test {public static void main(String[] args){HashTable hashTable=new HashTable(11) ;hashTable.insert(12);hashTable.insert("sjkljg");hashTable.insert(145);System.out.println(hashTable.contains(12));System.out.println(hashTable.contains(145));System.out.println(hashTable.contains("sjkljg"));hashTable.remove(12);System.out.println(hashTable.contains(12));}
}