LeetCode:206. Reverse Linked List

Reverse a singly linked list.

AC:

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