Java反转单链表

class Node {
    private int data;
    private Node nextNode;

    public Node(int data) {
        this.data = data;
    }
    public int getData() {
        return data;
    }
    public void setData(int data) {
        this.data = data;
    }
    public Node getNextNode() {
        return nextNode;
    }
    public void setNextNode(Node nextNode) {
        this.nextNode = nextNode;
    }
}

public class ReverseSingleList {

    public static Node reverse(Node head) {
        if (null == head || null == head.getNextNode()) {
            return head;
        }

        Node reversedHead = reverse(head.getNextNode());
        head.getNextNode().setNextNode(head);
        head.setNextNode(null);

        return reversedHead;
    }

    public static Node reverse2(Node head) {
        if (null == head || null == head.getNextNode()) {
            return head;
        }

        Node node1 = head;
        Node node2 = head.getNextNode();
        head.setNextNode(null);
        while (null != node2) {
            node1 = node2;
            node2 = node2.getNextNode();
            node1.setNextNode(head);
            head = node1;
        }

        return head;
    }

    public static void main(String[] args) {
        Node head = new Node(0);
        Node cur = head;
        Node tmp = null;

        // 构造一个长度为10的链表，保存头节点对象head
        for (int i = 1; i < 10; i++) {
            tmp = new Node(i);
            cur.setNextNode(tmp);
            cur = tmp;
        }

        //打印反转前的链表
        Node h = head;
        while (null != h) {
            System.out.print(h.getData() + " ");
            h = h.getNextNode();
        }

        //调用反转方法
        //head = reverse(head);
        head = reverse2(head);
        System.out.println("\n**************************");

        //打印反转后的结果
        while (null != head) {
            System.out.print(head.getData() + " ");
            head = head.getNextNode();
        }
    }
}

 

运行结果：

0 1 2 3 4 5 6 7 8 9

**************************

9 8 7 6 5 4 3 2 1 0