[LeetCode] 445. Add Two Numbers II

轉自LeetCode

You are given two linked lists representing two non-negative numbers. The most significant digit comes first 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.

Follow up:
What if you cannot modify the input lists? In other words, reversing the lists is not allowed.

Example:

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

<Solution>

這題是 Add Two Number 的衍生題

差別在於，這次 input 是正常的順序，沒有 reverse

因此，先把數值丟進 stack，再用 LIFO 的方式處理就好

要注意一點是，答案的 link list 也要按照正常順序