链表学习笔记--java语言实现

1、定义

链表是由一系列节点组成，每一个节点节点都包含两部分，一部分是元素数据本身，另一部分是指针下一个元素地址的指针。链表是一种物理上非连续、非顺序的存储结构，元素之间的顺序是通过每个元素的指针关联的。

2、链表的操作

创建、插入、删除、输出。

3、java实现（内部类创建节点）

package Link;class MyLink {    Node head = null;    class Node {        Node next = null; // 节点的指引，指向下一个节点        int data; // 节点内容        public Node(int data) {            this.data = data;        }    }    /*     * 向列表中插入数据     */    public void addNode(int data) {        Node newNode = new Node(data);        if (head == null) {            head = newNode;            return;        }        Node temp = head;        while (temp.next != null) {            temp = temp.next;        }        temp.next = newNode;    }    /*     * 指定位置插入数据     **/    public void addNode1(int index, int data) {        Node newNode = new Node(data);        Node temp = head;        if (index == 1) {            head = newNode;            head.next = temp;            return;        }        if (index > length()) {            Node temp1 = head;            // System.out.println("test");            while (temp1.next != null) {                temp1 = temp1.next;            }            temp1.next = newNode;            return;        }        int init = 1;        Node preNode = head;        Node curNode = head;        while (init != index) {            preNode = curNode;            curNode = curNode.next;            init++;        }        preNode.next = newNode;        newNode.next = curNode;    }    /*     * 删除第i个节点     */    public boolean delete(int i) {        if (i < 1 || i > length()) {            return false;        }        if (i == 1) {            head = head.next;            return true;        }        int j = 1;        Node preNode = head;        Node curNode = head;        while (j != i) {            preNode = curNode;            curNode = curNode.next;            j++;        }        if (j == i) {            preNode.next = curNode.next;            return true;        }        return false;    }    // 根据数据删除节点    public Node deleteByData(int data) {        Node curNode = head;        Node preNode = head;        while (curNode.data != data) {            if (curNode.next == null) {                return null;            }            preNode = curNode;            curNode = curNode.next;        }        if (curNode == head) {            head = head.next;        } else {            preNode.next = curNode.next;        }        return curNode;    }    /*     * 返回节点长度     */    public int length() {        int length = 0;        Node tmp = head;        while (tmp.next != null) {            length++;            tmp = tmp.next;        }        return length;    }    /*     * 打印链表     **/    public void printList() {        Node temp = head;        while (temp != null) {            System.out.print(temp.data + " ");            temp = temp.next;        }    }    // 链表反转    public Node ReverseIteratively(Node head) {        Node ReversedHead = head;        Node curNode = head;        Node preNode = null;        while (curNode != null) {            Node nextNode = curNode.next;            if (nextNode == null) {                ReversedHead = curNode;            }            curNode.next = preNode;            preNode = curNode;            curNode = nextNode;        }        this.head = ReversedHead;        return this.head;    }    // 查找单链表中间节点    public Node SearchMid(Node head) {        Node pNode = head, q = head;        while (pNode != null && pNode.next != null && pNode.next.next != null) {            pNode = pNode.next.next;            q = q.next;        }        System.out.println("Mid:" + q.data);        return q;    }    //查找倒数第k个元素    public Node findElem(Node head, int k) {        if (k < 1 || k > this.length()) {            return null;        }        Node pNode = head;        Node qNode = head;        for (int i = 0; i < k; i++) {            pNode = pNode.next;        }        while (pNode.next != null) {            pNode = pNode.next;            qNode = qNode.next;        }        return qNode;    }    //升序排序    public Node orderList() {        Node nextNode = null;        int tmp = 0;        Node curNode = head;        while(curNode.next != null){            nextNode = curNode.next;            while (nextNode != null) {                if (curNode.data > nextNode.data) {                    tmp = curNode.data;                    curNode.data = nextNode.data;                    nextNode.data = tmp;                }                nextNode = nextNode.next;            }            curNode = curNode.next;        }        return head;    }    //删除重复节点    public void deleteDuplecate(Node head) {        Node first = new Node(0);        first.next = head;        Node last = first;        Node p = head;        while(p!=null && p.next != null){            if (p.data == p.next.data) {                int value = p.data;                while(p!=null && p.data == value){                    p = p.next;                    last.next = p;                }            }else{                last = p;                p = p.next;            }        }        //去除重复元素//      while (p != null) {//          Node q = p;//          while(q.next != null){//              if (p.data == q.next.data) {//                  q.next = q.next.next;//              }else{//                  q = q.next;//              }//          }//          p = p.next;//      }    }    //递归输出链表    public void printListrecursive(Node head) {        if (head != null) {            System.out.print(head.data + " ");            printListrecursive(head.next);        }       }}

测试类

package Link;public class TestLink {    public static void main(String[] args) {        // TODO Auto-generated method stub        MyLink mLink= new MyLink();        mLink.addNode(2);        mLink.addNode(5);        mLink.addNode(5);        mLink.addNode1(1, 3);        mLink.addNode1(4,7);        mLink.addNode(2);        mLink.addNode(2);        mLink.addNode1(2,8);        mLink.addNode1(3,9);        mLink.addNode(10);        mLink.addNode(11);        mLink.printList();        System.out.println();//      mLink.deleteByData(2);        mLink.deleteDuplecate(mLink.head);//      mLink.ReverseIteratively(mLink.head);//      mLink.printList();//      mLink.SearchMid(mLink.head);//      mLink.orderList();        mLink.printListrecursive(mLink.head);    }}