Reverse a singly linked list.
Example:
Input: 1->2->3->4->5->NULL
Output: 5->4->3->2->1->NULL
Follow up:
A linked list can be reversed either iteratively or recursively. Could you implement both?
题解:
class Solution {
public:
ListNode* reverseList(ListNode* head) {
ListNode *pre = NULL, *cur = head;
while (head != NULL) {
cur = head;
head = head->next;
cur->next = pre;
pre = cur;
}
return cur;
}
};