用java实现单链表

对于一个单链表来说，要求有最基本的数据节点以及一些重要的方法。

方法应该有增删改查、定位、输出、获取链表长度、排序、链表读入、链表输出。下面是我用java写的单链表

public class List {

    public class Node{//定义节点
        public int data;
        public Node next;
        public Node(int data){
            this.data = data;
        }
    }

    private Node head;//头节点

    public Node getHead(){
        return head;
    }

    public int getLength()//得到链表长度
    {
        Node node = head;
        int k = 0;
        while(node != null){
            k++;
            node = node.next;
        }
        return k;
    }

    public Node Locate(int index){//定位位于第index位置的节点
        if(index <= 0)return null;
        Node node = head;
        int k = 1;
        while(node != null && k < index){
            k++;
            node = node.next;
        }
        return node;
    }

    public void input(int n){//链表输入
        if(n <= 0)return;
        Scanner reader = new Scanner(System.in);
        int value = reader.nextInt();

        head = new Node(value);
        Node node = head;
        int k = 1;
        while(k < n){
            k++;
            value = reader.nextInt();
            node.next = new Node(value);
            node = node.next;
        }
    }

    public void print(){//链表输出
        Node node = head;
        while(node != null){
            System.out.print(node.data  + " ");
            node = node.next;
        }
    }

    public void insert(int index, Node node){//链表插入
        if(index <= 0 || index > getLength())return;
        Node cur = Locate(index);
        node.next = cur.next;
        cur.next = node;
    }

    public void delete(int index){//删除节点
        if(index <= 0 || index > getLength())return;
        Node node = Locate(index - 1);

        Node del = node.next;
        node.next = del.next;
    }

    public void setData(int index, int data){//修改节点数据
        if(index <= 0 || index > getLength())return;
        Node node = Locate(index);
        node.data = data;
    }

    public int getData(int index){//得到节点数据
        if(index <= 0 || index > getLength())return -1;
        Node node = Locate(index);
        return node.data;
    }

    public void sort(){//用冒泡排序对链表进行排序
        Node cur = head;
        Node tmp = null;
        while(cur != tmp){
            while(cur.next != tmp){
                if(cur.data > cur.next.data){
                    int temp = cur.data;
                    cur.data = cur.next.data;
                    cur.next.data = temp;
                }
                cur = cur.next;
            }
            tmp = cur;
            cur = head;
        }
    }
}

测试代码如下:

public static void main(String[] args) {
        List L = new List();
        System.out.println("请输入链表中的数据");
        L.input(6);

        System.out.println("链表的长度为:" + L.getLength());
        System.out.println("排序后的链表为");
        L.sort();
        L.print();

        L.setData(4, 1000);
        System.out.println("把第4个数据修改为1000, 修改后如下");
        L.print();

        System.out.println("链表中第3个数据为: " + L.getData(3));

        L.delete(2);
        System.out.println("删除链表中的第2个数据后，结果如下");
        L.print();

    }

运行结果如下：