反转一个单向链表。

public class ReversingLinkedList {static class Node {int val;Node next;public Node(int val) {this.val = val;}public boolean hasNext() {return next != null;}}public static void main(String[] args) {//构造Node head = null;Node shift = null;for (int i = 1; i <= 10; i++) {Node node = new Node(i);if (head == null) {head = node;shift = node;} else {shift.next = node;shift = node;}}print(head);//反转Node tail = null;while (head.hasNext()) {//aNode tmp = head;//bhead = head.next;//ctmp.next = tail;//dtail = tmp;}head.next = tail;tail = head;print(tail);}static void print(Node node) {while (node.hasNext()) {System.out.print(node.val + " -> ");node = node.next;}System.out.println(node.val);}
}