65. Reverse Linked List

https://leetcode.com/problems/reverse-linked-list

Reverse Linked List - LeetCode

주어진 linked list를 reversed linked list로 만드는 문제

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:
    def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
        last = None
        while head != None:
            nextv = head.next
            head.next = last
            last = head
            if nextv == None:
                break
            head = nextv
        return head

처음에 last = head.val로 풀었더니 에러가 났다ㅎㅎ.....