002.两数相加

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4) Output: 7 -> 0 -> 8        342+465 = 807

• 题目描述：输入两个非空单链表，链表的每个结点的值是一个1位数整数，两个链表都是一个大整数每一位的逆序排序，求这两个链表代表的整数的和的链表值；

• 思路：1. 获取到两个数 然后相加 再新建list写入。2.每位想加时候考虑进位标志位

def addTwoNumbers(L1,L2):
	move = 0
	while L1:
		numOfL1 = L1.val * 10**move
		move += 1
		L1 = L1.next
	move = 0
	while L2:
		numOfL2 = L2.val * 10**move
		move += 1
		L2 = L2.next
	final = numOfL1 + numOfL2
	h = m = ListNode(0)
	if not final:
		return h
	while final:
		m.next = ListNode(final % 10)
		final = final/10
		m = m.next  # m.next 默认为空
	return h.next

# 带进位标志位的 函数 挺好
def addTwoNumbers(L1,L2):
	if L1 is None:
		return L2
	if L2 is None:
		return L1
	tmp = ListNode(0) # 最终要用的
	res = tmp
	flag = 0 #进位标记位
	while L1 or L2:
		tmpsum = 0
		if L1:
			tmpsum = L1.val
			L1 = L1.next
		if L2:
			tmpsum += L2.val
			L2 = L2.next
		tmpres = ((tmpsum + flag) % 10) # 余数
		flag = ((tmpsum + flag) // 10) # 进位
		res.next = ListNode(tmpres)
		res = res.next
	if flag:
		res.next = ListNode(1)
	res = tmp.next
	return res