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
/*** Definition for singly-linked list.* struct ListNode {* int val;* ListNode *next;* ListNode(int x) : val(x), next(NULL) {}* };*/class Solution {public:ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {ListNode * pHead = new ListNode(0);ListNode * pi = pHead;int carry = 0;while( l1 != NULL || l2 != NULL){int sum = (l1==NULL?0:l1->val) + (l2==NULL?0:l2->val) + carry;carry = sum / 10;pi->next = new ListNode(sum%10);pi = pi->next;if( l1 != NULL)l1 = l1->next;if( l2 != NULL)l2 = l2->next;}if(carry == 1)pi->next = new ListNode(carry);return pHead->next;}};
原文：http://www.cnblogs.com/zhxshseu/p/e4251984041337fe10dcf7e242d90493.html