" class="reference-link">Two Lists Sum Advanced

Question

  1. Given two numbers represented by two linked lists, write a function that returns sum list.
  2. The sum list is linked list representation of addition of two input numbers.
  4. Example
  6. Input:
  7.   First  List: 5->6->3  // represents number 563
  8.   Second List: 8->4->2  // represents number 842
  9. Output
  10.   Resultant list: 1->4->0->5  // represents number 1405
  12. Challenge
  14. Not allowed to modify the lists.
  15. Not allowed to use explicit extra space.

题解1 - 反转链表

在题 Two Lists Sum | Data Structure and Algorithm 的基础上改了下数位的表示方式，前者低位在前，高位在后，这个题的高位在前，低位在后。很自然地可以联想到先将链表反转，而后再使用 Two Lists Sum 的解法。

Reference