08. C function for insert after node in Linked List:-

8. Insert a node After a node In LL:-

Figure 4. Insert node after a  Node.

Logic:

• Find out previous pointer which will point on to node after which we have to add a node.
• To search previous pointer you may call search function which will return pointer whenever data will match in link list. 

Main Function code:

printf("\n Enter data for search a node after which data to be added:");
scanf("%d",&data); 
prev=search(head,data);
printf("\n Enter data of  node to be insert after:");
scanf("%d",&data1);
head= insert_after(head,data1,prev);
display(head);

C function for insert after node in Linked List:-

C function for insert after node:-

node* insert_after(node *head, int  data1, node* prev)

{

     // now first find the prev node, starting from the first node

    node *cursor = head;

    while(cursor != prev)

        cursor = cursor->next;

 // If cursor is not NULL then create a new node having data and pointer of cursor->next

    if(cursor != NULL)

    {

        node* new_node = create(data1,cursor->next);

        cursor->next = new_node; // Assign cursor-.next pointer to new node

        return head;

    }

    else

    {

        return NULL;

    }

}