Add two numbers@leetcode

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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

» Solve this problem

这题思路很简单，这个算法里很巧妙地用了当l1 or l2是null的时候用0来代替的做法，很简洁。

另外还要注意c＋＋里面指针的运算，要新开辟node呢。