【leetcode】206. Reverse Linked List(easy)

反转链表

// 206. Reverse Linked List
ListNode* Solution::reverseList(ListNode* head)
{

	if (head == NULL || head->next == NULL)
		return head;

	ListNode * p = head; // p指向当前处理的原链表的位置
	ListNode * res = head;
	ListNode * pHead = head->next;
	res->next = NULL; // 初始化第一个节点，next指向一个空
	
	while (pHead)
	{
		p = pHead;
		pHead = pHead->next;

		p->next = res;
		res = p;
	}
	return res;
}

Runtime: 8 ms, faster than 100.00% of C++ online submissions for Reverse Linked List.
Memory Usage: 9.1 MB, less than 85.68% of C++ online submissions for Reverse Linked List.