单向链表反转

public class ReverseLinkListNode {
    static Node reverse(Node head) {
        Node nextNode = head;
        Node firstNode = null;
        while (nextNode != null) {
            Node n = nextNode;
            nextNode = n.next;
            n.next = firstNode;
            firstNode = n;
        }
        return firstNode;
    }
 
 
    static String print(Node head) {
        StringBuilder sb = new StringBuilder("Head->");
        Node p = head;
        while (p != null) {
            sb.append(p.data).append("->");
            p = p.next;
        }
        sb.append("null");
        return sb.toString();
}
    public static void main(String[] args) {
        Node node1 = new Node(1);
        Node node2 = new Node(2);
        Node node3 = new Node(3);
        Node node4 = new Node(4);
        Node node5 = new Node(5);
        node1.next = node2;
        node2.next = node3;
        node3.next = node4;
        node4.next = node5;
        System.out.println(print(node1));
        System.out.println(print(reverse(node1)));
    }
}
 
class Node {
    int data;
    Node next;
 
    public Node(int data) {
        this.data = data;
    }
    public String toString() {
        return "Node{" +
                "data=" + data +
                ", next=" + next +
                '}';
    }
}