题解 | #反转链表#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param head ListNode类 
     * @return ListNode类
     */
    ListNode* ReverseList(ListNode* head) {
        if(head==NULL){
            return head;
        }
        ListNode *new_head = NULL;
        while (head)
        {
            ListNode *next = head->next;
            head->next = new_head;
            new_head = head;
            head = next;
        }
        return new_head;
    }
};