feat: Add linked_list.py

Author: yyossy5

src/linked_list.py

@@ -0,0 +1,34 @@
+"""
+Linked List operations module.
+
+This module provides functionality for manipulating singly linked lists,
+including operations like reversing the list.
+"""
+
+
+class ListNode:
+    def __init__(self, val=None, next=None):
+        self.val = val
+        self.next = next
+
+
+def reverse_linked_list(head: ListNode) -> ListNode:
+    """
+    Reverses a singly linked list.
+
+    Args:
+        head (ListNode): The head node of the linked list
+
+    Returns:
+        ListNode: The head node of the reversed linked list
+    """
+    prev = None
+    current = head
+
+    while current is not None:
+        next_temp = current.next
+        current.next = prev
+        prev = current
+        current = next_temp
+
+    return prev