public class Linkedlist {
   public class Node{
       
       private Person p;
       private Node next;
       public Node(Person p){
           this.p=p;
       }
    /**
     * @return the p
     */
    public Person getP() {
        return p;
    }
    /**
     * @param p the p to set
     */
    public void setP(Person p) {
        this.p = p;
    }
       
   }
   private Node head;
   private String  key;
   public Linkedlist(){
      head=new Node(null);
       head.next=head;
      
   }
   
   public void insertNode(Person p){
     Node node=new Node(p);
     Node temp=head;
       if(head.next!=head){
           while(temp.next!=head){
               temp=temp.next;
           }
           temp.next=node;
           node.next=head;
       }else{
           head.next=node;
           node.next=head;
       }
   }
   public Node find(String key){
       Node temp=head;
       
       if(temp.next!=head){
            while(!key.equals(temp.next.p.getAge())){
               temp=temp.next;
           }
           return temp.next;
       }else{
           return null;
       }
       
   }
   
   public int delete(String key){
       Node temp=head;
       if(temp.next!=head){
           while(!key.equals(temp.next.p.getAge())){
               temp=temp.next;
           }
           temp.next=temp.next.next;
           return 1;
       }else{
           return -1;
       }
   }
   public void deleteNode(){ //從頭結點開始刪除
       if(head.next!=head){
           head.next=head.next.next;
       }else{
           System.out.println("沒有可刪除的節點");
       }
   }
   public void display(){
       Node temp=head;
       while(temp.next!=head){
           temp=temp.next;
           System.out.println(temp.p);
       }
   }
   
}

import java.math.BigInteger;


public class Hashmap {
    private Linkedlist[] arr;
    public Hashmap(int maxnum){
        arr=new Linkedlist[maxnum];
    }
   
   public void insert(Person p){
       int key=hashCode(p.getAge());
       if(arr[key]==null){
           arr[key]=new Linkedlist();
       }
       arr[key].insertNode(p);
   }
   /*查找數據
    * 
    * */ 
   public Person find(String age) {
       
    
        return arr[hashCode(age)].find(age).getP();
    
   }
   public void delete(String age){
       int key=hashCode(age);
     System.out.println(arr[key].delete(age)); 
      
   }
   
   public int hashCode(String age){
      
       BigInteger hashVal=new BigInteger("0");
       BigInteger pow27=new BigInteger("1");
       for(int i=age.length()-1;i>=0;i--){
           int letter=age.charAt(i)-96;
           BigInteger letterB=new BigInteger(String.valueOf(letter));
           hashVal=hashVal.add(letterB.multiply(pow27));
           pow27=pow27.multiply(new BigInteger(String.valueOf(27)));
       }
       return hashVal.mod(new BigInteger(String.valueOf(arr.length))).intValue();
   }
}

public class TestHash {

    public static void main(String[] args) {
        
        Hashmap h=new Hashmap(4);
        Person p1=new Person("a","李四");
        Person p2=new Person("ct","王五");
        Person p3=new Person("b","張三");
        h.insert(p1);
        h.insert(p2);
        h.insert(p3);
        //h.delete("b");
        System.out.println(h.find("b"));
        System.out.println(h.find("a"));
        System.out.println(h.find("ct"));
        
        
        
    }

}