链表相加

对于链表中的每个节点依此相加，同时记录节点相加后的进位情况

主要有以下两种情况

1.链表一样长的情况

2.链表不一样长的情况，需要处理计算完成后剩余节点

我采用产生一个新的链表依此记录相应节点的结果。

欢迎一起交流

def listAdd(a,b):

    if a is None or a.next is None:

        return

    if b is None or b.next is None:

        return

    sum = 0   #两个节点相加的和

    p1 = a.next

    p2 = b.next

   c = 0 #进位数

    res = Node()

    res.next = None

    p = res#结果链表的末尾位置引用，用于结果插入

    while p1 is not None and p2 is not None:

        cur = Node()

        cur.next = None

        sum = p1.x+p2.x+c

        cur.x = sum%10

        c = sum/10

        p.next = cur

        p = cur

        p1 = p1.next

        p2 = p2.next

if p1 is  None:#p2链表比p1长的时候

        while p2 is not None:

            cur = Node()

            cur.next = None

            sum = p2.x + c

            cur.x = sum%10

            c = sum/10

            p.next = cur

            p = cur

            p2 = p2.next

    if p2 is  None:

        while p1 is not None:

            cur = Node()

            cur.next = None

            sum = p1.x + c

            cur.x = sum%10

            c = sum/10

            p.next = cur

            p = cur

            p1 = p1.next

if c == 1:  #若计算完成还有进位

        cur = Node()

        cur.next = None

        cur.x = 1

        p.next = cur

    return res