WAP to SumTwo Number Which are represented by node in linked list

#include<stdio.h>
#include<malloc.h>
 
/* Link list node */
struct node
{
int data;
struct node* next;
};
 
/* Function to reverse the linked list */
static void reverse(struct node** head_ref)
{
struct node* prev = NULL;
struct node* current = *head_ref;
struct node* next;
while (current != NULL)
{
next = current->next;
current->next = prev;
prev = current;
current = next;
}
*head_ref = prev;
}
 
/* Function to push a node */
void push(struct node** head_ref, int new_data)
{
/* allocate node */
struct node* new_node =
(struct node*) malloc(sizeof(struct node));
 
/* put in the data */
new_node->data = new_data;
 
/* link the old list off the new node */
new_node->next = (*head_ref); 
 
/* move the head to point to the new node */
(*head_ref) = new_node;
}
 
 
 
struct node* addition (struct node* temp1, struct node* temp2)
{
 
struct node* prev = NULL;
int carry = 0,a,b,result;
 
while (temp1 || temp2) //while both lists exist
{
 
if(temp1) a=temp1->data;
else a=0;
 
if(temp2) b=temp2->data;
else b=0;
 
 
 
 
result = carry;
if(temp1)
result+=temp1->data;
if(temp2)
result+=temp2->data;
 
 
carry=result/10;
 
struct node * newnode = (struct node*) malloc (sizeof(struct node));
newnode->data=(result)%10;
newnode->next = prev;
 
prev=newnode;
if(temp1)
temp1=temp1->next;
if(temp2)
temp2=temp2->next;
}
return prev;
 
}
void printList(struct node *node)
{
while(node != NULL)
{
printf("%d ", node->data);
node = node->next;
}
} 
 
/* Drier program to test above function*/
int main(void)
{
/* Start with the empty list */
struct node* head = NULL;
struct node* head1 = NULL;
struct node* head2 = NULL;
 
 
/* Created Linked list is 1->2->3->4->5->6->7->8 */
 
push(&head1, 4);
push(&head1, 3);
push(&head1, 2);
push(&head1, 1);
 
reverse(&head1); 
 
push(&head2, 6);
push(&head2, 5);
push(&head2, 4);
 
reverse(&head2); 
 
head=addition(head1,head2); 
 
 
 
printList(head);
 
return(0);
}

TC O(n+m) where n,m are the number of digits in given numbers.
SC O(1)
Run Here https://ideone.com/j4Z8Z