Day571.哈希表 -数据结构和算法Java

package com.achang.hashtable;



public class HashTableDemo {
    public static void main(String[] args) {
        HashTable hashTable = new HashTable(3);
        hashTable.add(new Emp(1,"阿昌1"));
        hashTable.add(new Emp(2,"阿昌2"));
        hashTable.list();
        System.out.println("==========");
        hashTable.findEmpById(3);
        System.out.println("=================");
        hashTable.deleteById(1);
        System.out.println("=============");
        hashTable.list();

    }
}


class Emp {
    
    public int id;

    
    public String name;

    
    public Emp next;

    public Emp(int id, String name) {
        this.name = name;
        this.id = id;
    }
}


class EmplinkedList {
    
    public Emp head;

    
    public void add(Emp emp) {
        if (head == null) {
            head = emp;
            return;
        }

        Emp temp = head;
        while (true){
            if (temp.next == null){
                break;
            }
            temp = temp.next;//后移，直到最后
        }
        temp.next = emp;
    }


    //删除
    public void deleteById(int id){
        Emp temp = head;
        boolean flag = false;
        while (true) {
            if (temp.next == null) {
                System.out.println("已经到链表的最后");
                break;
            }
            if (temp.next.id == id) {
                System.out.println("找到了待删除的前一个节点");
                flag = true;
            }
            temp = temp.next;
        }
        if (flag) {
            temp.next = temp.next.next;
        } else {
            System.out.println("要删除的节点不存在");
        }
    }

    //查找
    public Emp findEmpById(int id){
        if (head == null){
            System.out.println("链表为空");
            return null;
        }
        Emp temp = head;
        while (true){
            if (temp.id == id){
                break;
            }
            if (temp.next == null){//没找到
                temp = null;
                break;
            }
            temp = temp.next;
        }
        return temp;
    }

    //遍历
    public void list(){
        if (head == null) {
            System.out.println("链表为空");
            return;
        }
        Emp temp = head;
        while (true){
            System.out.print(temp.id+temp.name+"--->");
            if (temp.next ==null){
                System.out.println();
                break;
            }
            temp = temp.next;
        }
    }

}


class HashTable{
    private EmplinkedList[] emplinkedLists;
    private int size;

    public HashTable(int size){
        this.emplinkedLists = new EmplinkedList[size];
        this.size = size;
        //初始化每一条链表
        for (int i = 0; i < this.emplinkedLists.length; i++) {
            emplinkedLists[i] = new EmplinkedList();
        }

    }

    public void deleteById(int id){
        int index = id % size;
        emplinkedLists[index].deleteById(id);
    }

    public void findEmpById(int id){
       int index =  id % size;
        Emp emp = emplinkedLists[index].findEmpById(id);
        if (emp != null){
            System.out.println("找到了："+emp.id+emp.name);
        }else {
            System.out.println("没有找到");
        }
    }

    public void add(Emp emp){
        //根据id添加
        int index = emp.id % size;
        emplinkedLists[index].add(emp);
    }

    public void list(){
        for (EmplinkedList emplinkedList : emplinkedLists) {
            emplinkedList.list();
        }
    }

}