python中利用鏈表計算兩個非負整數之和（鏈表類型非列表）

LeetCode裏的一個題，沒注意到輸入類型是列表格式，所以用類結點形式的鏈表寫出來了，做個記錄

class ListNode:
    def __init__(self, x):
        self.val = x
        self.next = None

class Solution:
    def appendResult(self, result, pre):
        p = ListNode(None)
        if result.val == None:
            result.val = pre.val
        else:
            p = result
            while p.next!=None:
                p = p.next
            p.next = pre    #17
        return result
        
    def addTwoNumbers(self, l1, l2):
        result = ListNode(None); count1 = 0; count2 = 0; Cout = 0
        
        #確定哪條鏈長
        pl1 = l1; pl2 = l2
        while pl1 != None:
            pl1 = pl1.next
            count1 += 1
        while pl2 != None:
            pl2 = pl2.next
            count2 += 1
        if count1 >= count2:
            lon = l1; short = l2
        else:
            lon = l2; short = l1
        
        # 開始相加
        while lon!=None or short!=None:
            pr = ListNode(None)  
            if short != None:
                pr.val = (Cout + lon.val + short.val)%10
                Cout = int((Cout + lon.val + short.val)/10)
                self.appendResult(result, pr)
                short = short.next
                lon = lon.next
            elif short == None and lon != None:
                pr.val = (Cout + lon.val)%10
                Cout = int((Cout + lon.val)/10)
                self.appendResult(result, pr)
                lon = lon.next
        if Cout ==1:
            self.appendResult(result, ListNode(Cout))

        return result