Given two numbers represented by two linked lists of size N and M. The task is to return a sum list. The sum list is a linked list representation of the addition of two input numbers from the last.

Singly-linked list需要reverse, 用stack. 最终结果要恢复成input list 那样的sequence方向, 用stack一个个pop()刚好就可以做到. You have two numbers represented by a linked list, where each node contains a single digit. The digits are ...