java单链表操作

java的单链表的一些操作

package listTest;/** * 自定义链表设计 *  */public class MyLink {    Node head = null; // 头节点    /**     * 链表中的节点，data代表节点的值，next是指向下一个节点的引用     *      * @author zjn     *     */    class Node {        Node next = null;// 节点的引用，指向下一个节点        int data;// 节点的对象，即内容        public Node(int data) {            this.data = data;        }    }    /**     * 向链表中插入数据  如果是第一个节点就放在头，否则一直往后走     *      * @param d     */    public void addNode(int d) {        Node newNode = new Node(d);// 实例化一个节点        if (head == null) {            head = newNode;            return;        }        Node tmp = head;        //新加的节点放到最后面        while (tmp.next != null) {            tmp = tmp.next;        }        tmp.next = newNode;    }    /**     *      * @param index:删除第index个节点     * @return     */    public boolean deleteNode(int index) {    //节点在第一个和最后一个的范围之内        if (index < 1 || index > length()) {            return false;        }        //第一个节点        if (index == 1) {            head = head.next;            return true;        }        int i = 1;        Node preNode = head;        Node curNode = preNode.next;        while (curNode != null) {            if (i == index) {//如果循环到了当前的节点就把当前的next指向给消掉                preNode.next = curNode.next;                return true;            }            preNode = curNode;            curNode = curNode.next;            i++;        }        return false;    }    /**     *      * @return 返回节点长度     */    public int length() {        int length = 0;        Node tmp = head;        while (tmp != null) {            length++;            tmp = tmp.next;        }        return length;    }       public void printList() {        Node tmp = head;        while (tmp != null) {                    System.out.print(tmp.data + "  ");            tmp = tmp.next;        }        System.out.println();    }              /**     * 排序     *      * @return     */    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     * 传进来一个头节点，循环每个节点与之后的节点 进行比较，如果遍历到一个值和之后的某个值相等，就把此值的指针删除     */    public static void deleteDuplecate(Node head) {        Node p = head;        while (p != null) {            Node q = p;//q把当前的指针记下来你            while (q.next != null) {//单链表的最后一个节点的next为空                if (p.data == q.next.data) {                    q.next = q.next.next;                } else                    q = q.next;            }            p = p.next;        }    }    /**     * 从尾到头输出单链表，采用递归方式实现     *      * @param pListHead     */    public static void printListReversely(Node pListHead) {        if (pListHead != null) {            printListReversely(pListHead.next);            System.out.println("printListReversely:" + pListHead.data);        }    }    /**     * 查找单链表的中间节点     *      * @param head     * @return     */    public Node SearchMid(Node head) {        Node p = this.head,          q = this.head;        while (p != null && p.next != null && p.next.next != null) {                    p = p.next.next;            q = q.next;        }        System.out.println("Mid:" + q.data);        return q;    }    /**     * 查找倒数 第k个元素     *      * @param head     * @param k     * @return     */    public Node findElem(Node head, int k) {        if (k < 1 || k > this.length()) {            return null;        }        Node p1 = head;        Node p2 = head;        for (int i = 0; i < k; i++)// 前移k步            p1 = p1.next;        while (p1 != null) {            p1 = p1.next;            p2 = p2.next;        }        return p2;    }    /**     * 判断链表是否有环，单向链表有环时，尾节点相同     *      * @param head     * @return     */    public boolean IsLoop(Node head) {        Node fast = head, slow = head;        if (fast == null) {            return false;        }        while (fast != null && fast.next != null) {            fast = fast.next.next;            slow = slow.next;            if (fast == slow) {                System.out.println("该链表有环");                return true;            }        }        return !(fast == null || fast.next == null);    }    /**     * 找出链表环的入口     *      * @param head     * @return     */    public Node FindLoopPort(Node head) {        Node fast = head, slow = head;        while (fast != null && fast.next != null) {            slow = slow.next;            fast = fast.next.next;            if (slow == fast)                break;        }        if (fast == null || fast.next == null)            return null;        slow = head;        while (slow != fast) {            slow = slow.next;            fast = fast.next;        }        return slow;    }              /**     * 链表反转     *      * @param head     * @return     */    public  void ReverseIteratively(Node head,MyLink list ) {        Node pReversedHead = head;        Node pNode = head;        Node pPrev = null;        while (pNode != null){            Node pNext = pNode.next;//pNode是不是尾节点            if (pNext == null) {                pReversedHead = pNode;            }            pNode.next = pPrev;            //pNext = pPrev;            pPrev = pNode;            pNode = pNext;        }        this.head = pReversedHead;        //return this.head;    }        /**     * 在不知道头指针的情况下删除指定节点     *      * @param n     * @return     */    public static boolean deleteNodeNoHead(Node n) {            if (n == null || n.next == null)            return false;        int tmp = n.data;        n.data = n.next.data;        n.next.data = tmp;        n.next = n.next.next;        System.out.println("删除成功！");        return true;    }    public static void main(String[] args) {        MyLink list = new MyLink();                list.addNode(5);        list.addNode(3);        list.addNode(1);        //list.addNode(5);        list.addNode(7);        list.addNode(5);               boolean flag= list.IsLoop(list.head);        if(flag==true){        System.out.println("有环");        }else{        System.out.println("无环");                }       /* Node n=list.findElem(list.head, 2);        deleteNodeNoHead(n);        list.printList();*/       /* list.addNode(6);        list.addNode(2);        list.addNode(2);        list.addNode(55);        list.addNode(36);*/       // System.out.println("linkLength:" + list.length());        //System.out.println("head.data:" + list.head.data);        //deleteDup2(list.head);             //printListReversely(list.head);       //list.printList();       //list. ReverseIteratively(list.head);      // Node n= list.findElem(list.head, 3);             //  System.out.println("原始的：");        //list.printList();      // list. reverse2(list.head);       //System.out.println(n.data);       //list.SearchMid(list.head);     //  System.out.println("翻转之后：========");       list.printList();       /*  list.deleteNode(4);        System.out.println("After deleteNode(4):");        list.printList();              Node node1= list.new Node(1);        deleteNode11(node1);        System.out.println("After 1:");        list.printList();*/    }}