Time: 50 ms (82.65%), Space: 16.6 MB (48.65%) - LeetHub

Author: RootProgrammer

0002-add-two-numbers/0002-add-two-numbers.py

@@ -0,0 +1,28 @@
+# 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]:
+        result = ListNode()
+        current = result
+        carry = 0
+
+        while l1 or l2 or carry:
+            value1 = l1.val if l1 else 0
+            value2 = l2.val if l2 else 0
+
+            # new digit
+            value = value1 + value2 + carry
+            # if carry is 10+
+            carry = value // 10
+            value = value % 10
+            current.next = ListNode(value)
+
+            # update pointers
+            current = current.next
+            l1 = l1.next if l1 else None
+            l2 = l2.next if l2 else None
+
+        return result.next