You are given two non-empty linked lists representing two non-negative integers. 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.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.
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* l3 = new ListNode(0); ListNode* ptr = l3; int tmp = 0; while(1){ if(l1 != NULL ){ tmp += l1->val ; l1 = l1->next; } if( l2 != NULL){ tmp += l2->val; l2 = l2->next; } ptr->val = tmp%10; tmp /= 10; if(l1 != NULL || l2 !=NULL || tmp != 0){ ptr->next = new ListNode(0); ptr = ptr->next; } else break; } return l3; } };