feat(work): add Add Two Numbers solution

work/1/Medium/Linked List/2.add-two-numbers.py

@@ -0,0 +1,61 @@
+"""
+2. Add Two Numbers
+Difficulty: Medium
+https://leetcode.com/problems/add-two-numbers/
+
+──────────────────────────────────────────────────
+
+You are given two non-empty linked lists representing two
+non-negative integers. The digits are stored in reverse order, and
+each of their nodes contains a single digit. Add the two numbers and
+return the sum as a linked list.
+
+You may assume the two numbers do not contain any leading zero,
+except the number 0 itself.
+
+
+
+Example 1:
+
+Input: l1 = [2,4,3], l2 = [5,6,4]
+Output: [7,0,8]
+Explanation: 342 + 465 = 807.
+
+Example 2:
+
+Input: l1 = [0], l2 = [0]
+Output: [0]
+
+Example 3:
+
+Input: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
+Output: [8,9,9,9,0,0,0,1]
+
+
+
+Constraints:
+
+        • The number of nodes in each linked list is in the range [1, 100].
+
+        • 0 <= Node.val <= 9
+
+• It is guaranteed that the list represents a number that does not
+have leading zeros.
+"""
+
+
+# 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]:
+        head = ListNode()
+        carry = 0
+        l1curr = head
+        l2curr = head
+        while head:
+            l1.val + l2.val