数据结构与算法（3）-链表

package ch04;
/**
 * 链表，相当于火车
 * @author Administrator
 *
 */
public class LinkList {
	//头结点
	private Node first;
	public LinkList(){
		first = null;
	}
	/*
	 * 插入一个结点，在头结点后进行插入
	 */
	public void insertFirst(long value){
		Node node = new Node(value);
		node.next = first;
		first = node;
	}
	/*
	 * 删除一个结点，在头结点后进行删除
	 */
	public Node deleteFirst(){
		Node tmp = first;
		first = tmp.next;
		return tmp;
	}
	/*
	 * 显示方法
	 */
	public void display(){
		Node current = first;
		while(current != null){
			current.display();
			current = current.next;
		}
		System.out.println();
	}
	/*
	 * 查找方法
	 */
	public Node find(long value){
		Node current = first;
		while(current.data != value){
			if(current.next ==  null){
				return null;
			}
			current = current.next;
		}
		return current;
		
	}
	/*
	 * 删除方法，根据数据域来进行删除
	 */
	public Node delete(long value){
		Node current =  first;
		Node previous =  first;
		while(current.data != value){
			if(current.next == null){
				return null;
			}
			previous = current;
			current = current.next;
		}
		if(current == first){
			first = first.next;
		}else{
			previous.next = current.next;
		}
		return current;
	}
	
	public static void main(String[] args) {
		LinkList linkList = new LinkList();
		linkList.insertFirst(34);
		linkList.insertFirst(23);
		linkList.insertFirst(12);
		linkList.insertFirst(0);
		linkList.insertFirst(-1);
		
		linkList.display();
		
		linkList.deleteFirst();
		linkList.display();
		
		Node node = linkList.find(23);
		node.display();
		
		Node node1 = linkList.delete(0);
		node1.display();
		System.out.println();
		linkList.display();
		
	}
}