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 || !head->next) return head;

        ListNode* Pre = nullptr,*Phead = head,*temp = nullptr;
        while (Phead) {
            temp = Phead->next;
            Phead->next = Pre;
            Pre = Phead;
            Phead = temp;

        }
        return Pre;


    }
};