[Add] Leetcode > 2. Add Two Numbers

Author: Joie-Kim

Leetcode/add_two_numbers.py

@@ -0,0 +1,32 @@
+# 2. Add Two Numbers
+
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+
+class Solution:
+    def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]:
+        carry = 0
+        result = temp = ListNode()
+        
+        while l1 or l2 or carry:
+            l1_val = 0
+            l2_val = 0
+            
+            if l1:
+                l1_val = l1.val
+                l1 = l1.next
+            if l2:
+                l2_val = l2.val
+                l2 = l2.next
+            
+            sum_val = l1_val + l2_val + carry
+            
+            temp.next = ListNode(sum_val % 10)
+            temp = temp.next
+            
+            carry = sum_val // 10
+        
+        return result.next