补充3：单链表的实现

链表类

	public class Node{
		int data;
		Node next;
		public Node(int data){
			this.data = data;
		}
	}

1.插入元素创建链表

    当一个链表的最后一个节点的next为null时即为链表的末尾节点，现在末尾节点后继续添加节点，先将新节点放在最后，然后修改上一个末尾节点的next。

	public  void add(int data){
		Node node = new Node(data);
		if(head==null){
			head = node;
		}else{
			last.next = node;
		}
		last = node;
	}

2.在指定位置插入节点

    先找到要插入的位置的前一节点，并将前一节点的next指向新节点，新节点的next则指向前一节点之前的next

	public void insert(int location,int data){
		Node node = head;
		int i = 0;
		while(node!=null&&i<location-2){
			node = node.next;
			i++;
		}
		Node newnode = new Node(data);
		newnode.next = node.next;
		node.next = newnode;
	}

3.删除指定位置的节点

    类似于插入指定节点，先找出要删除的节点位置的前一节点，将next改为next的next

	public void delete(int location){
		Node node = head;
		int i=0;
		while(node!=null&&i<location-2){
			node = node.next;
			i++;
		}
		node.next = node.next.next;
	}

4.修改节点数据

    找出该节点位置，修改数值即可

	public void modify(int location,int data){
		Node node = head;
		int i=0;
		while(node!=null&&i<location-1){
			node = node.next;
			i++;
		}
		node.data = data;
	}

5.打印链表

	public void print(){
		Node node = head;
		while(node!=null){
			System.out.print(node.data);
			node = node.next;
		}
	}

6.链表长度

	public int length(){
		int length = 0;
		Node node = head;
		while(node!=null){
			length++;
			node = node.next;
		}
		return length;
	}

7.查找指定位置节点

public Node get(int location){  
    Node node=head;  
    int i=1;  
    while(node!=null&&i<location){  
        node=node.next;  
        i++;  
    }  
    return node;  
}

完整测试

public class javatest {
		Node head =null;
		Node last =null;	
	
	public class Node{
		int data;
		Node next;
		public Node(int data){
			this.data = data;
		}
	}
	
	public  void add(int data){
		Node node = new Node(data);
		if(head==null){
			head = node;
		}else{
			last.next = node;
		}
		last = node;
	}
	
	public void insert(int location,int data){
		Node node = head;
		int i = 0;
		while(node!=null&&i<location-2){
			node = node.next;
			i++;
		}
		Node newnode = new Node(data);
		newnode.next = node.next;
		node.next = newnode;
	}
	
	public void delete(int location){
		Node node = head;
		int i=0;
		while(node!=null&&i<location-2){
			node = node.next;
			i++;
		}
		node.next = node.next.next;
	}
	
	public void modify(int location,int data){
		Node node = head;
		int i=0;
		while(node!=null&&i<location-1){
			node = node.next;
			i++;
		}
		node.data = data;
	}
	
	public void print(){
		Node node = head;
		while(node!=null){
			System.out.print(node.data);
			node = node.next;
		}
	}
	
	public int length(){
		int length = 0;
		Node node = head;
		while(node!=null){
			length++;
			node = node.next;
		}
		return length;
	}
	
	
	public static void main(String[] args){
		javatest link = new javatest();
		link.add(1);
		link.add(2);
		link.add(3);
		link.add(4);
		link.add(5);
		link.add(6);
		link.add(7);
		link.add(8);
		link.add(9);
		link.add(10);
		System.out.println(link.length());
		System.out.println("head.data:" + link.head.data);
		link.print();
		System.out.println();
		link.modify(1, 888);
		System.out.println("after modipfy:" );
		link.print();
		System.out.println();
		link.delete(6);
		System.out.println("after delete:" );
		link.print();
		
	}
}

输出结果：

10
head.data:1
12345678910
after modipfy:
8882345678910
after delete:
888234578910