package search;public class SeparateChainingHashST<Key , Value> {private int N; //键值对总数private int M;//散列表的大小private SequentialSearchST<Key, Value>[] st;public SeparateChainingHashST() {// TODO Auto-generated constructor stubthis(997);}//初始化，为每一个hash值都创建一个链表 M个public SeparateChainingHashST(int M) {// TODO Auto-generated constructor stubthis.M = M;st = (SequentialSearchST<Key, Value>[]) new SequentialSearchST[M];for(int i=0; i<M; i++) {st[i] = new SequentialSearchST();}}private int hash(Key key) {return (key.hashCode() & 0x7fffffff) % M;}public Value get(Key key) {return (Value)st[hash(key)].get(key);}public void put(Key key, Value val) {st[hash(key)].put(key, val);}public static void main(String[] args) {// TODO Auto-generated method stub
}}

package search;//链表，内部类
public class SequentialSearchST<Key, Value>{public SequentialSearchST() {super();// TODO Auto-generated constructor stub
    }private Node head;//链表头指针//结点类 内部类private class Node{Key key;Value val;Node next;//下一个结点指针public Node() {}public Node(Key key, Value val, Node next) {this.key = key;this.val = val;this.next = next;}}//顺序查找public Value get(Key key) {Node x = head;while(x != null) {if(x.key.equals(key)) {return x.val;}x = x.next;}return null;}//尾插法public void put(Key key, Value val) {//先考虑key存在的情况Node x = head;while(true) {if(x.key.equals(key)) {x.val = val;return;}//如果下一个结点不为空，则继续向下迭代。为空，则直接把新节点插入即可if(x.next != null)x = x.next;else {x.next = new Node(key, val, null);}}}//头插法public void putt(Key key, Value val) {Node x = head;//先搜索一遍防止键 存在while(x != null) {if(x.key.equals(key)) {x.val = val;return;}x = x.next;}//如果 不存在则将该新节点指向旧的头指针， 新头指针指向 它head = new Node(key, val, head);}}

package search;import java.util.Random;public class LinearProbingHashST<Key , Value> {private int N = 0;//当前使用量private int M = 16;//默认容量大小为M//并行数组private Key[] keys;private Value[] vals;public LinearProbingHashST() {// TODO Auto-generated constructor stub
        alloc();}public LinearProbingHashST(int cap) {M = cap;alloc();}private void alloc() {keys = (Key[])new Object[M];vals = (Value[]) new Object[M];}private int hash(Key key) {return (key.hashCode() &  0x7fffffff) % M;}//插入 查询 定理：  目标键与hash值所在的键  位于同一条长键之中，中间不可能有空隙public void show() {for(int i=0; i<M; i++) {if(keys[i] != null)System.out.println(keys[i].toString() + ":" +vals[i].toString());}}//插入操作 冲突 循环后移再探测public void put(Key key, Value val) {//保证使用量不超过额定容量的一半//System.out.println("put :" + N + " " + M/2);if(N > M/2) {resize(2*M);
//            System.out.println("*************************resize*************************" + M);
//            show();
//            System.out.println("**************************************************");
        }int index = hash(key);for(; keys[index] != null;  index = (index+1) % M) {if(keys[index].equals(key)) {vals[index] = val;return ;//如果该键已经存在则改值后 return
            }}keys[index] = key;vals[index] = val;N++;}//这种赋值方式不行 思考一下为什么  从hash值的模出发private void resizes(int cap) {// TODO Auto-generated method stubKey[] ks =  (Key[]) new Object[2*cap];Value[] vs =  (Value[]) new Object[2*cap];for(int i=0; i<M; i++) {ks[i] = keys[i] ;vs[i] = vals[i] ;}keys =  ks;vals = vs;M = cap;}private void resize(int cap) {LinearProbingHashST<Key , Value> t;t = new LinearProbingHashST<Key , Value>(cap);for(int i=0; i<M; i++) {if(keys[i] != null)t.put(keys[i], vals[i]);}this.keys = t.keys;this.vals = t.vals;this.M = t.M;}public Value get(Key key) {int index = hash(key);//首先算出hash值得到预期位置，如果正好这个位置的键等于key，那么命中，直接返回对应的val//如果发现key不相等，则说明发生冲突，由插入算法可知，要查找的键必然是和冲突键位于同一组长 键之中//继续查找直到遇到空为止 遇到空说明该键不存在for(int i = index; keys[i] != null; i = (i+1) % M) {if(keys[i].equals(key)) {return vals[i];}}return null;}//根据插入查询定理 目标键与hash值所在的键处于同一个长键之中，中间不能有缝隙//如果因为删除一个键后导致中间断裂，会导致查询失效//G H KLOMN  U  ML hash值相等  KN hash值不等//只能将该【长键中】所删除的键置为空然后将其右边的所有键重新插入public void delete(Key key) {int index = hash(key);int pos = index;boolean flag = false;for(; keys[index] != null; index = (index + 1) % M) {if(keys[index].equals(key)) {//找到这个键了 把位置记录下来一会用，index继续增加得到边界flag = true;pos = index;keys[index] = null;vals[index] = null;N--;}}//没找到需要删除的键 就算了if(!flag)return ;//从pos+1的位置 到 index-1的位置所有键需要重新弄插入 注意位置序号需要取模pos = pos + 1;pos %= M;while(pos != index) {Key k = keys[pos];Value v = vals[pos];keys[pos] = null;vals[pos] = null;put(k , v);//重新插入pos = (pos + 1) % M;//后移pos位置
        }}public static void main(String[] args) {// TODO Auto-generated method stubLinearProbingHashST<Integer , Integer> hashST;hashST = new LinearProbingHashST<Integer, Integer>();Random r = new Random();for(int i=0; i<1500000; i++) {Integer key = new Integer(r.nextInt(10000000));Integer value = new Integer(r.nextInt(10000000));//System.out.println("key = " + key + " value = " + value);
            hashST.put(key, value);//System.out.println("N = " + hashST.N + " M = " + hashST.M);
        }//System.out.println("put 操作完毕");hashST.put(88888, 88888);hashST.put(88888, 99999);//System.out.println(hashST.get(88888));System.out.println("删除前*****************");//hashST.show();//hashST.delete(88888);
        System.out.println("删除后*****************");//hashST.show();System.out.println(hashST.get(88888));System.out.println("OK");}}