链表_leetcode2

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

class Solution(object):
    def addTwoNumbers(self, l1, l2):
        """
        :type l1: ListNode
        :type l2: ListNode
        :rtype: ListNode
        """

        def getNum(head):

            cur = head
            weight = 1
            nums = 0

            while cur :
                nums += cur.val * weight
                weight = weight * 10
                cur = cur.next

            return nums


        nums1  = getNum(l1)
        nums2 = getNum(l2)



        res = nums1 + nums2
        head = ListNode(0)
        p = head

        if res == 0:
            return head

        while res:
            val = res % 10

            p.next = ListNode(val)
            p = p.next
            res = res / 10


        return  head.next