LeetCode-206. Reverse Linked List

链表逆转

/** * 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) {        ListNode *old_head, *new_head, *temp;        old_head = head;        new_head = temp = NULL;        while( old_head ) {            temp = old_head->next;            old_head->next = new_head;            new_head = old_head;            old_head = temp;        }        return new_head;    }};