Update katie.md

Author: KatieONell

problems/2181/katie.md

@@ -8,7 +8,19 @@ When we get to another 0, we want to repeat this process.
 The final 0 is annoying... I'll add a statement where if the next.next is None, then break out of the loop
 
 ## Attempted solution(s)
-```        node = head
+```
+# Definition for singly-linked list.
+# class ListNode(object):
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+class Solution(object):
+    def mergeNodes(self, head):
+        """
+        :type head: Optional[ListNode]
+        :rtype: Optional[ListNode]
+        """
+        node = head
         while node.next != None:
             if node.next.val != 0:
                 node.val += node.next.val
@@ -20,3 +32,4 @@ The final 0 is annoying... I'll add a statement where if the next.next is None,
                 node = node.next
         return head
 ```
+<img width="609" alt="Screen Shot 2024-07-04 at 4 18 32 PM" src="https://github.com/KatieONell/leetcode-solutions/assets/12962290/68480f6c-a1ee-4745-888b-dcbc7ac9ceab">