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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.

Example:

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
Explanation: 342 + 465 = 807.

Original Quiz in C++

/**
 * 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) {
        
    }
};

Solution 1 - C++

twonumbers.cpp
/**
 * Definition for singly-linked list.
 * struct ListNode {
 * int val;
 * ListNode *next;
 * ListNode(int x) : val(x), next(NULL) {}
 * };
 */

#define MSELECT(A,B) (A?A:(B?B:NULL))
#define MSELECTNEXT(A,B) (A?A->next:(B?B->next:NULL))

class Solution {
public:
 ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
 ListNode *n=new ListNode(0);
 if (l1) n->val+=l1->val;
 if (l2) n->val+=l2->val;
 if (n->val>9)
 {
 ListNode *next=MSELECTNEXT(l1,l2);
 if (next)
 {
 next->val += 1; 
 }
 else
 {
 ListNode *nc=new ListNode(1);
 ListNode *p=MSELECT(l1,l2);
 p->next=nc;
 }
 n->val -=10; 
 }
 if (MSELECT(l1,l2))
 n->next = addTwoNumbers((l1?l1->next:NULL), (l2?l2->next:NULL));
 else n->next =NULL;
 return n;
 }
};

https://leetcode.com/problems/add-two-numbers/description/

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