12. Delete a node in the middle of the linked list

Figure 8. Delete Middle/Any Node.

Logic:

first find out pointer of node to be detete by calling search() function as a nd or tmp pointer

then travesre whole linked list till cursor match with nd pointer. 

If nd pointer match with head then call remove_front function.

If nd pointer match with last node then call remove_back function.

If above two condition fails to find out nd pointer position means nd pointer lies in between.

Hence find out cursor pointer which locate before nd pointer and assign cursor->next to tmp->next also make temp->next finally NULL .

Then free memory allocated to tmp node free(tmp) .

Main Function code:

printf("\n Enter data of node to be delete:");

scanf("%d",&data);

nd=search(head,data);

head=remove_any(head,nd);

display(head);

C function for remove any node/ middle node in linked list :-

first search node pointer i.e. nd using search function

node* remove_any(node* head,node* nd)

{

     if(nd == head) // if node is first node then simply call remove front function

    {

        head = remove_front(head);

        return head;

    }

     if(nd->next == NULL) // if node is last node then  call remove back function

    {

        head = remove_back(head);

        return head;

    }

// if the node is in the middle then traverse linked list to find out nd

    node* cursor = head;

    while(cursor != NULL)

    {

        if(cursor->next = nd)

            break;

        cursor = cursor->next;

    }

 // after finding nd take one dummy pointer say tmp and change the pointer

    if(cursor != NULL)

    {

        node* tmp = cursor->next;

        cursor->next = tmp->next;

        tmp->next = NULL;

        free(tmp);

    }

    return head;

}