leetcode add to numbers python实现

Add Two Numbers

You are given two linked lists representing two non-negative numbers. 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.

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

看了半天没看懂，这鸟题想说什么 ，看的如下才懂:

即 342+465= 807 引自：http://blog.youkuaiyun.com/xshalk/article/details/8148854

好吧，看懂别人再想了想 也写了一个，用多了c++的各种容器，对于这种操作链接的东西都不熟了

struct ListNode
{
	ListNode *pNext;
	int		 iNum;
};

//就是模拟加法
ListNode *add_two_numbers(ListNode *pL1, ListNode *pL2)
{
	if (pL1 == NULL || pL2 == NULL)
	{
		return NULL;
	}
	//进位
	int carry = 0;
	ListNode *pRet = NULL;
	ListNode *pTail = pRet;
	ListNode *pT1 = pL1, *pT2 = pL2;
	while (pT1 != NULL || pT2 != NULL)
	{
		int v1, v2;
		if (pT1 != NULL)
		{
			v1 = pT1->iNum;
		}
		else
		{
			v1 = 0;
		}
		if (pT2 != NULL)
		{
			v2 = pT2->iNum;
		}
		else
		{
			v2 = 0;
		}

		//如果加完结果大于10，取个位
		int sum = (v1 + v2 + carry) % 10;
		//取十位保存
		carry = pRet->iNum / 10;

		if (pRet == NULL)
		{
			pRet = new ListNode;
			pRet->iNum = sum;
			pRet->pNext = NULL;
			pTail = pRet;
		}
		else
		{
			pTail->pNext = new ListNode;
			pTail->pNext->iNum = sum;
			pTail->pNext->pNext = NULL;
			pTail = pTail->pNext;
		}
	}
	if (carry != 0)
	{
		pTail->pNext = new ListNode;
		pTail->pNext->iNum = carry;
		pTail->pNext->pNext = NULL;
		pTail = pTail->pNext;
	}
}