单链表Java实现

单链表Java代码实现

public class MyLinkedList<T> {


    private Node mHead;

    MyLinkedList() {
    }

    public void add(T data, int index) {
        if (index < 0 || index > size()) {
            throw new IllegalArgumentException("index is error");
        }
        if (index == 0) {
            addHeadNode(data);
        }

        if (index == size()) {
            addTailNode(data);
        }

        Node curNode = mHead;
        int pos = 0;
        Node preNode = null;

        while (curNode.next != null) {
            if (pos == index) {
                Node node = new Node();
                node.data = data;
                node.next = preNode.next;
                preNode.next = node;
            }
            pos++;
            preNode = curNode;
            curNode = curNode.next;
        }

    }

    public int size() {
        if (mHead == null) {
            return 0;
        }
        if (mHead.next == null) {
            return 1;
        }
        Node curNode = mHead;
        int size = 0;
        while (curNode.next != null) {
            size++;
            curNode = curNode.next;
        }
        return size;
    }

    public boolean delete(T value) {
        if (size() == 0) {
            return false;
        }
        if (mHead.data.equals(value)) {
            mHead = mHead.next;
            return true;
        }
        Node curNode = mHead;
        while (curNode.next != null) {
            if (curNode.next.data.equals(value)) {
                curNode.next = curNode.next.next;
                return true;
            }
        }
        return false;


    }

    public T get(int i) {
        if (mHead == null) {
            return null;
        }

        Node curNode = mHead;
        int pos = 0;
        while (curNode.next != null) {
            curNode = curNode.next;
            pos++;
            if (pos == i) {
                return curNode.data;
            }
        }
        return curNode.data;
    }

    /**
     * 头插法
     *
     * @param value
     */
    public void addHeadNode(T value) {
        Node node = new Node(value);
        if (mHead == null) {
            mHead = node;
        } else {
            node.next = mHead;
            mHead = node;
        }

    }

    /**
     * 尾插法
     *
     * @param value
     */
    public void addTailNode(T value) {

        Node node = new Node(value);
        if (mHead == null) {
            mHead = node;
        } else {
            Node last = mHead;
            while (last.next != null) {
                last = last.next;
            }
            last.next = node;
        }

    }

    public Node reverse() {
        if (null == mHead || null == mHead.next)
            return mHead;
        Node pre = mHead;
        Node cur = mHead.next;
        while (null != cur.next) {
            Node tmp = cur.next;
            cur.next = pre;
            pre = cur;
            cur = tmp;
        }
        cur.next = pre;
        mHead.next = null;

        String s = cur.data.toString();
        while (cur.next != null) {
            cur = cur.next;
            s += " " + cur.data.toString();
        }
        System.out.println( s);
        return cur;
    }




    class Node {
        T data;
        Node next;

        Node() {

        }

        public Node(T data) {
            this.data = data;
            this.next = null;
        }
    }

    @NonNull
    @Override
    public String toString() {
        if (mHead == null) {
            return null;
        }
        String linkString = "";
        Node curNode = mHead;
        if (curNode.next == null) {
            return curNode.data.toString();
        }else {
            while (curNode.next != null) {
                linkString += " " + curNode.data.toString();
                curNode = curNode.next;
            }
            linkString += " " + curNode.data.toString();
            return linkString;
        }

    }


}