两数相加

微信图片_20191218171817.jpg

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
        tmp = ListNode(0)
        res = tmp
        flag = 0
        while l1 or l2:
            tmpSum = 0
            if l1:
                tmpSum = l1.val
                l1 = l1.next
            if l2:
                tmpSum += l2.val
                l2 = l2.next
            tmpRes = (tmpSum+flag) % 10
            flag = (tmpSum+flag) // 10
            res.next = ListNode(tmpRes)
            res = res.next
        if flag:
            res.next = ListNode(1)
        res = tmp.next
        del tmp
        return res