両端チェーンテーブル、双方向チェーンテーブル(java)

package com.cwq.ch05;

import com.cwq.ch04.Node;

/** 
 *     ，      
 * @author Carpoor  
 * @date 2019 1 29  
 */
public class MyFirstLastLinkedList {

	private Node first;
	private Node last;
	
	public MyFirstLastLinkedList() {
		first = null;
	}
	
	/**
	 *     ，     
	 */
	public void insertFirst(long value) {
		Node node = new Node(value);
		if (isEmpty()) {
			last = node;
		}
		node.next = first;
		first = node;
	}
	
	/**
	 *     ，     
	 */
	public void insertLast(long value) {
		Node node = new Node(value);
		if (isEmpty()) {
			first = node;
		} else {
			last.next = node;
		}
		last = node;
	}
	
	/**
	 *     ，   
	 */
	public Node deleteFirst() {
		Node tmp = first;
		if (tmp.next == null) {
			last = null;
		}
		first = first.next;
		return tmp;
	}
	
	/**
	 *     
	 */
	public void display() {
		Node current = first;
		while (current != null) {
			current.display();
			current = current.next;
		}
		System.out.println();
	}
	
	/**
	 *     
	 */
	public Node find(long value) {
		Node current = first;
		while (current.data != value) {
			if (current.next == null) {
				return null;
			}
			current = current.next;
		}
		return current;
	}
	
	/**
	 *     
	 */
	public Node delete(long value) {
		Node current = first;
		Node prev = first;
		while (current.data != value) {
			if (current.next == null) {
				return null;
			}
			prev = current;
			current = current.next;
		}
		if (current == first) {
			first = first.next;
		} else {
			prev.next = current.next;
		}
		
		return current;
	}
	
	public boolean isEmpty() {
		return first == null;
	}
}

package com.cwq.ch05;

/** 
 * @author Carpoor  
 * @date 2019 1 30  
 */
public class TestFirstLastMyLinkedList {

	public static void main(String[] args) {
		MyFirstLastLinkedList list = new MyFirstLastLinkedList();
		list.insertFirst(50);
		list.insertFirst(40);
		list.insertFirst(30);
		list.insertLast(50);
		list.insertLast(40);
		list.insertLast(30);
		list.display();
		
		while(!list.isEmpty()) {
			list.deleteFirst();
			list.display();
		}
		
	}
	
}

package com.cwq.ch05;

/** 
 *     ，      
 * @author Carpoor  
 * @date 2019 1 29  
 */
public class MyDoubleLinkedList {

	private Node first;
	private Node last;
	
	public MyDoubleLinkedList() {
		first = null;
	}
	
	/**
	 *     ，     
	 */
	public void insertFirst(long value) {
		Node node = new Node(value);
		if (isEmpty()) {
			last = node;
		}else {
			first.prev = node;
		}
		node.next = first;
		first = node;
	}
	
	/**
	 *     ，     
	 */
	public void insertLast(long value) {
		Node node = new Node(value);
		if (isEmpty()) {
			first = node;
		} else {
			last.next = node;
			node.prev = last;
		}
		last = node;
	}
	
	/**
	 *     ，   
	 */
	public Node deleteFirst() {
		Node tmp = first;
		if (tmp.next == null) {
			last = null;
		}else {
			first.next.prev = null;
		}
		first = first.next;
		return tmp;
	}
	
	/**
	 *     ，   
	 */
	public Node deleteLast() {
		Node tmp = last;
		if (tmp.prev == null) {
			first = null;
		}else {
			tmp.prev.next = null;
		}
		last = last.prev;
		return tmp;
	}
	
	/**
	 *     
	 */
	public void display() {
		Node current = first;
		while (current != null) {
			current.display();
			current = current.next;
		}
		System.out.println();
	}
	
	/**
	 *     
	 */
	public Node find(long value) {
		Node current = first;
		while (current.data != value) {
			if (current.next == null) {
				return null;
			}
			current = current.next;
		}
		return current;
	}
	
	/**
	 *     
	 */
	public Node delete(long value) {
		Node current = first;
		Node prev = first;
		while (current.data != value) {
			if (current.next == null) {
				return null;
			}
			prev = current;
			current = current.next;
		}
		if (current == first) {
			first = first.next;
		} else {
			prev.next = current.next;
		}
		
		return current;
	}
	
	public boolean isEmpty() {
		return first == null;
	}
}

package com.cwq.ch05;

/** 
 * @author Carpoor  
 * @date 2019 1 31  
 */
public class TestMyDoubleLinkedList {

	public static void main(String[] args) {
		MyDoubleLinkedList list = new MyDoubleLinkedList();
		list.insertFirst(50);
		list.insertFirst(40);
		list.insertFirst(30);
		list.insertLast(50);
		list.insertLast(40);
		list.insertLast(30);
		list.display();
		
		while(!list.isEmpty()) {
			list.deleteFirst();
			list.display();
		}
		System.out.println("------------------------------------");
		list.insertFirst(50);
		list.insertFirst(40);
		list.insertFirst(30);
		list.insertLast(50);
		list.insertLast(40);
		list.insertLast(30);
		list.display();
		
		while(!list.isEmpty()) {
			list.deleteLast();
			list.display();
		}
	}
	
}