Add Two Number

add_two_number.py

class ListNode:
    def __init__(self, val=0, nextt=None):
        self.val = val
        self.nextt = nextt
    def size(self):
        i = 1
        nextt = self.nextt
        while nextt != None:
            nextt = nextt.nextt
            i += 1
        return i

    def addLast(self, val):
        pred = self
        nextt = self.nextt
        while nextt != None:
            pred = nextt
            nextt = nextt.nextt
        pred.nextt = ListNode(val=val)
    def toArray(self):
        tab = []
        tab.append(self.val)
        nextt = self.nextt
        while nextt != None:
            tab.append(nextt.val)
            nextt = nextt.nextt
        return tab
        

class Solution:
    def addTwoNumber(self, l1:ListNode, l2:ListNode):
        return self.__sumSucc(l1, l2) if l1.size() > l2.size() else self.__sumSucc(l2, l1)
    
    def __sumSucc(self, l1:ListNode, l2:ListNode):
        resultList = ListNode()
        firstNode = False
        rest = 0
        _l1 = l1
        _l2 = l2
        while _l1:
            sum_num = _l1.val + _l2.val + rest if _l2 != None else _l1.val + rest 
            rest = int(str(sum_num)[0]) if sum_num > 9 else 0
            used_digit = int(str(sum_num)[1]) if sum_num > 9 else sum_num
            if not firstNode:
                firstNode = True
                resultList.val = used_digit
            else:
                resultList.addLast(used_digit)
            _l1 = _l1.nextt
            _l2 = _l2.nextt if _l2 != None else None
        return resultList
            
listOne = ListNode(2, ListNode(4, ListNode(val=3)))
listTwo = ListNode(5, ListNode(6, ListNode(val=4)))
solution = Solution()
listResult = solution.addTwoNumber(listOne, listTwo)
listResult.toArray()