Quetion
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.
Example
Input:(2->4->3)+(5->6->4) Output:7->0->8
Solution
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) {val=x;} * } */ public class Solution { public ListNode addTwoNumbers(ListNode l1, ListNode l2) { ListNode ret=new ListNode(0); ListNode cur=ret; int sum = 0; while (true) { if (l1!=null) { sum+=l1.val; l1=l1.next; } if (l2!=null) { sum+=l2.val; l2=l2.next; } cur.val=sum % 10; sum /= 10; if (l1 != null || l2 != null || sum != 0) { cur=(cur.next=new ListNode(0)); } else { break; } } return ret; } } 