2. Add Two Numbers

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

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 contains a single digit. Add the two numbers and return the sum as a linked list.
You may assume the two numbers do not contain any leading zero, except the number 0 itself.

Solution

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode* Addnode(int val){
    struct ListNode * new = malloc(sizeof(struct ListNode));
    new -> val = val;
    new -> next = NULL;
    return new;
    
}

struct ListNode* addTwoNumbers(struct ListNode* l1, struct ListNode* l2){
    struct ListNode * head = NULL;
    struct ListNode * current = NULL;
    struct ListNode * rear = NULL;
    int c = 0; 
    int result = 0;
    
    while(l1!=NULL||l2!=NULL){
        result = c +(l1?l1->val:0)+(l2?l2->val:0);
        c = (result>9)?1:0;
        result = result%10;
        current = Addnode(result);
        if(!head)
            head = current;
        else
            rear ->next = current;
        rear = current;
        if(l1)
            l1=l1->next;
        if(l2)
            l2=l2->next;
        
    }
    if(c == 1)
        rear->next = Addnode(1);
    return head;
    
}