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

Add Two Numbers.cpp

/**
 * 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) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        return addNodes(l1, l2, 0);
    }
    
    ListNode *addNodes(ListNode *l1, ListNode *l2, int carry)
    {
        if(!l1 && !l2 && carry==0) return NULL;
        int a=0, b=0; 
        if(l1){ a=l1->val; }
        if(l2){ b=l2->val; }
        int value=a+b+carry; 
        ListNode *head=new ListNode(value%10);
        head->next=addNodes(l1? l1->next: NULL , l2?l2->next:NULL, value/10);
        return head;
    }
};

Add Two Numbers.java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        // Start typing your Java solution below
        // DO NOT write main() function
        return calculate(l1, l2, 0); 
    }
    
        ListNode calculate(ListNode l1, ListNode l2, int carry)
       {
        if(l1==null&&l2==null&&carry==0) return null; 
        if(l1==null&&l2==null&&carry!=0) return new ListNode(1); 
	int temp=(l1==null? 0: l1.val)+ (l2==null? 0: l2.val)+ carry; 
	ListNode result=new ListNode(temp%10); 
	result.next=calculate(l1==null? null: l1.next, l2==null? null: l2.next, temp/10); 
        return result;
	 }
}