Time: 46 ms (54.85%), Space: 15.4 MB (98.14%) - LeetHub

Author: ataslim0343

206-reverse-linked-list/206-reverse-linked-list.py

@@ -1,43 +1,19 @@
 # Definition for singly-linked list.
-# class ListNode(object):
+# class ListNode:
 # def __init__(self, val=0, next=None):
 # self.val = val
 # self.next = next
-
-
-# Time=O(n)
-# Space=O(n)
-
-class Solution(object):
- def reverseList(self, head):
- """
- :type head: ListNode
- :rtype: ListNode
- """
-#------------------Approach 1-----------------------#
-
-
- # arr=[]
- # node = head
- # temp=head
- # while(node):
- # arr.append(node.val)
- # node=node.next
- # for i in range(len(arr)-1,-1,-1):
- # temp.val=arr[i]
- # temp=temp.next
- # return head
-
-
-#------------------Approach 2-----------------------#
-
- curr=head
+class Solution:
+ def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
  prev=None
- while(curr!=None):
- next=curr.next
+ curr=head
+ nextt=None
+ while(curr):
+ nextt=curr.next
  curr.next=prev
  prev=curr
- curr=next
- return prev
-
+ curr=nextt
+ head=prev
+ return head
+