LEETCODE 206

Reverse a singly linked list.

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Hint:
A linked list can be reversed either iteratively or recursively. Could you implement both?

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旋转指针，比较简单的题。
/**
* 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* nxt = head;
while(nxt)
{
ListNode* temp = nxt->next;
nxt->next = pre;
pre = nxt;
nxt = temp;
}
return pre;
}
};