Day 14: Attempt 2: 92_Reverse_Linked_List_II

Readme.md

@@ -54,6 +54,7 @@ Remember, the 75 Hard Challenge is about personal growth and discipline. Stay co
 - Day 12: [2. Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)
 - Day 12: [21. Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)
 - Day 13: [138. Copy List with Random Pointer](https://leetcode.com/problems/copy-list-with-random-pointer/)
+- Day 14: [92. Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/)
 
 
 

top_interview_questions/75_hard/Linked List/92_Reverse_Linked_List_II.py

@@ -5,4 +5,27 @@
 #         self.next = next
 class Solution:
     def reverseBetween(self, head: Optional[ListNode], left: int, right: int) -> Optional[ListNode]:
-        pass
+
+        if not head or left == right:
+            return head
+
+        dummy = ListNode(0)
+        dummy.next = head
+        prev = dummy
+
+        for _ in range(left-1):
+            prev = prev.next
+
+        stack = []
+        current = prev.next
+
+        for _ in range(right-left+1):
+            stack.append(current)
+            current = current.next
+
+        while stack: 
+            prev.next = stack.pop()
+            prev = prev.next
+        prev.next = current
+
+        return dummy.next