题目：原题链接（简单）
标签：链表
解法 | 时间复杂度 | 空间复杂度 | 执行用时 |
Ans 1 (Python) | O(N) | O(1) | 56ms (14.20%) |
Ans 2 (Python) | O(N) | O(1) | 44ms (77.44%) |
Ans 3 (Python) |
解法一：
class Solution:
def reverseList(self, head: ListNode) -> ListNode:
if head:
ans = ListNode(0)
ans.next = head
node = head.next
head.next = None
while node:
temp = ans.next
ans.next = node
node = node.next
ans.next.next = temp
return ans.next解法二（合并解法一的指针交换）：
class Solution:
def reverseList(self, head: ListNode) -> ListNode:
if head:
ans = ListNode(0)
ans.next, node, head.next = head, head.next, None
while node:
ans.next, node.next, node = node, ans.next, node.next
return ans.next
