[Leetcode]206. Reverse Linked List

Reverse a singly linked list.

/** * 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 || head->next == NULL)            return head;        ListNode* pre = NULL;        ListNode* curr = head;        while (curr != NULL)         {            ListNode* post = curr->next;            curr->next = pre;            pre = curr;            curr = post;        }        return pre;    }};