单向链表

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单向链表（单链表）是链表的一种，其特点是链表的链接方向是单向的，对链表的访问要通过顺序读取从头部开始。

Link zh.png

[编辑]动态单链表

单向链表的数据结构可以分为两部分：数据域和指针域，数据域存储数据，指针域指向下一个储存节点的地址。
package linklist2;

public class LinkList {
   private Node firstNode;
        private int length;

        public LinkList(){
            clear();
        }

        public void clear(){
            firstNode=null;
            length=0;
        }

        public Node getFirstNode(){
            return firstNode;
        }

        public boolean add(int data){
            Node node=new Node(data);
            if(isEmpty()){
                firstNode=node;
            }else{
                Node lastNode=getNodeAt(length);
                lastNode.next=node;
            }
            length++;
            return true;
        }

        public boolean isEmpty(){
            //return length==0;
            //use assert to get more details when error occurs
            boolean result;
            if(length==0){
                assert firstNode==null;
                result=true;
            }else{
                assert firstNode!=null;
                result=false;
            }
            return result;
        }

        public void reverse(){
            if(firstNode==null)return;
            Node p=firstNode;//use p to traverse every node
            Node previous=null;
            while(p.next!=null){
                Node q=p.next;// save p.next first because the next sentence changes p.next
                p.next=previous;
                previous=p;
                p=q;
            }
            p.next=previous;
            firstNode=p;//should not be ignored
        }

        //recursive
        public Node reverseRecursive(Node p){
            if(p==null)return null;
            if(p.next==null){
                firstNode=p;
                return p;
            }
            Node q=p.next;
            //reverse the remaining nodes,except p
            //when recursive returns,you can regard the link as a link that has just two elements: p-->q
            //so the last reversing is simple: q.next=p;p.next=null;
            Node ph=reverseRecursive(q);
            q.next=p;
            p.next=null;
            System.out.print("("+ph.data+")");//ph.data=1,always
            return ph;
        }

        public void display(){
            Node node=firstNode;
            while(node!=null){
                System.out.print(node.data+" ");
                node=node.next;
            }
            System.out.println();
        }
        private Node getNodeAt(int position){
            Node re=firstNode;
            if(!isEmpty()&&position>1&&position<=length){
                for(int count=1;count<position;count++){
                    re=re.next;
                }
            }
            return re;
        }

        //use inner class
        private class Node{
            private int data;
            private Node next;

            private Node(int data){
                this.data=data;
                next=null;
            }
        }
}

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测试一下哦

public static void main(String[] args) {
       // TODO Auto-generated method stub
       LinkList list=new LinkList();
            int[] a={1,2,3,4,5};
            for(int each:a){
                list.add(each);
            }
            list.display();
            list.reverse();
            list.display();
            list.reverseRecursive(list.getFirstNode());
            list.display();
        }