easy
Reverse a singly linked list.
Hint:A linked list can be reversed either iteratively or recursively. Could you implement both?
这道题暂时只会iterative的写法， 需要补充recursive的写法
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode reverseList(ListNode head) {
if (head == null){
return null;
}
if (head.next == null){
return head;
}
ListNode prev = null;
ListNode curt = head;
while (curt != null){
ListNode temp = curt.next;
curt.next = prev;
prev = curt;
curt = temp;
}
return prev;
}
}
