206

Author: Jeldo

reverse-linked-list/jeldo.py

@@ -0,0 +1,15 @@
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+class Solution:
+    # O(n), n = len(nodes)
+    def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
+        tail = None
+        while head:
+            temp = head.next
+            head.next = tail
+            tail = head
+            head = temp
+        return tail