[LeetCode 206]反转链表 Reverse Linked List

图片来自本题的一个题解
https://leetcode-cn.com/problems/reverse-linked-list/solution/die-dai-di-gui-jie-fa-by-sunshy/

image.png

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        if(head==NULL)return NULL;
        ListNode *p1 = head;
        ListNode *p2 = p1->next;
        while (p2!=NULL)
        {
            p1->next = p2->next;
            p2->next = head;
            head = p2;
            p2=p1->next;
        }
        return head;
    }
    
};