题解 | #两个链表生成相加链表#

模拟进位 c

反转链表后再运算会更简单

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

#
# 
# @param head1 ListNode类 
# @param head2 ListNode类 
# @return ListNode类
#
class Solution:
    def addInList(self , head1 , head2 ):
        c = 0
        head = ListNode(-1)
        p1 = self.reverse(head1)
        p2 = self.reverse(head2)
        p = head
        while p1 != None and p2 != None:
            val = (p1.val + p2.val + c)% 10
            tmp = ListNode(val)
            p.next = tmp
            p = p.next
            c = int ((p1.val + p2.val + c) /10)
            p1 = p1.next
            p2 = p2.next
        while p1 != None:
            val = (p1.val + c) % 10
            c = int ((p1.val +c)/ 10) 
            tmp = ListNode(val)
            p.next = tmp
            p = p.next
            p1 = p1.next
        while p2 != None:
            val = (p2.val + c) % 10
            c = int ((p2.val +c) / 10)
            tmp = ListNode(val)
            p.next = tmp
            p = p.next
            p2 = p2.next
        if c == 1:
            tmp = ListNode(1)
            p.next = tmp
            p = p.next
        return self.reverse(head.next)
    def reverse(self,head):
        pre = None
        p = head
        while p != None:
            tmp = pre
            pre = p
            p = p.next
            pre.next = tmp
        return pre