LeetCode_209_ReverseLinkedList

题目解析:

注意这里是没有头结点的链表，每个节点都有值。

解法：

public static ListNode reverseList(ListNode head) {
    if(null == head)
        return head;
    ListNode preNode = null;
    ListNode nextNode = null;
    while(null != head.next){
        nextNode = head.next;
        head.next = preNode;
        preNode = head;
        head = nextNode;
    }
    head.next = preNode;
    return head;
}