Leetcode 2. Add Two Numbers

class Solution:
    def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
# 1번 풀이
#         head = temp = ListNode(0)
#         carry = 0

#         while l1 or l2 or carry:
#             temp1 = l1.val if l1 else 0
#             temp2 = l2.val if l2 else 0
#             tempSum = temp1 + temp2 + carry
            
#             temp.next = ListNode(tempSum % 10)
#             temp = temp.next
#             carry = tempSum // 10

#             if l1:
#                 l1 = l1.next
#             if l2:
#                 l2 = l2.next

#         return head.next
# 2번 풀이
        ans = cur = ListNode(0)
        temp_l1 = l1
        temp_l2 = l2
        while True:
            if temp_l1 and temp_l2:
                cur.next = ListNode(temp_l1.val + temp_l2.val)
                temp_l1 = temp_l1.next
                temp_l2 = temp_l2.next
                cur = cur.next
            elif temp_l1 and not temp_l2:
                cur.next = ListNode(temp_l1.val)
                temp_l1 = temp_l1.next
                cur = cur.next
            elif temp_l2 and not temp_l1:
                cur.next = ListNode(temp_l2.val)
                temp_l2 = temp_l2.next
                cur = cur.next
            else:
                break
        
        temp = ans.next
        carry = 0
        
        while temp:
            if carry:
                temp.val += carry
                carry = 0
            if temp.val > 9:
                temp.val -= 10
                carry += 1
            
            if temp.next:
                temp = temp.next
            else:
                if carry:
                    temp.next = ListNode(carry)
                break
            
        return ans.next
            

https://leetcode.com/problems/add-two-numbers/