Hi All,

Can the previous node of a given node in a singly linked list be deleted?

Thanks
Angshuman

Sure, as long as you have a pointer to the node that is before the link that
you want to delete.  Make sure you draw it out on paper first so that you
understand what has to be done.

| Hi All,
|
| Can the previous node of a given node in a singly linked list be deleted?
|
| Thanks
| Angshuman
|
|

Yes, like this (pseudocode)

        /*---     search item to delete   ---*|
        |*    but remeber the previous one   */
        previtem=NULL;
        for (item=root;item!=searcheditem;item=item->next)
                previtem=item;

        /*--- remove item form list ---*/
        if (previtem) {
                previtem->next = searcheditem->next;
                }
        else {
                root = searcheditem->next;
                }

        /*--- delete the item ---*/
        free(searcheditem);

Oops,
wasn't reading to good.
Just look up the previous item like the "searcheditem" and delete this
one.

yes, it can be done.
The algo is
(I am assuming that the starting addr of the list is known let  us say slist)

ptr1 = p; /*pointer to the node*/
ptr2 = slist;
ptr3= slist;
ptr2 = ptr2->link;
while (ptr2->link->data != ptr1->data)
{
    ptr2 = ptr2->link;
   ptr3 = ptr3->link;

/*After exiting from this loop
*  ptr3 = ptr to the prev node to be deleted
*  ptr2 = ptr to the node to be deleted
*  ptr1 = ptr to the next victim node*/

delete(ptr2,ptr3);

HTH
Archna

armittal.vcf < 1K Download

Angshuman Mukherjee a crit dans le message

Try magic...

--
HS
CLC-FAQ: http://www.eskimo.com/~scs/C-faq/top.html
It's specified. But anyone who writes code like that should be
transmogrified into earthworms and fed to ducks. -- Chris Dollin CLC