package main

import . "nc_tools"

/*
 * type ListNode struct{
 *   Val int
 *   Next *ListNode
 * }
 */

/**
 *
 * @param pHead ListNode类
 * @return ListNode类
 */
func ReverseList(pHead *ListNode) *ListNode {
	if pHead == nil || pHead.Next == nil {
		return pHead
	}
	var newHead *ListNode
	for pHead != nil {
		pNext := pHead.Next  // 保留未反转链表
		pHead.Next = newHead // 节点反转
		newHead = pHead      // 更新已反转链表
		pHead = pNext        // 更新当前节点
	}
	return newHead
}