Thread: please help me..How can I delete node at location 1 from a single link list ?

Hello all,
Please help me.
I have write a serial link list program.Here i can delete node at any location except at location 1(head).

head of link list is at location 1.

Please tell me where i am going wrong ?
please give me a hint.

Code:

void deletenode(node**ptr,int loc)
{
     node *temp,*s,*r;
     s = *ptr;
     if(count(*ptr)<loc)
     {
        printf("\n out of list");                   
     }
     else
     {
         while(loc>1)
         {
          temp = s;
          s= s->next;         
          loc--;  
         }
         temp->next = s->next;
            
     }
         
}

Thanks,
Gunjan

Deleting the first node is a special case, because there is no node before it for which you have to change the ->next member. Just add a special case in there for if count == 1:

Code:

void deletenode(node**ptr,int loc)
{
     int n_nodes;
     node *temp,*s,*r;
     s = *ptr;
     n_nodes = count(*ptr);  // use a temp variable so you don't have to call count() twice
     if (n_nodes < loc)
          // error
     else if (n_nodes == 1)
          // delete first node
     else
          // normal node delete

Woah, major mistake in the code I posted. It should be:

Code:

     if (n_nodes < loc)
          // error
     if (loc == 1)
          // delete first node
     else
          // normal node delete

Hi all,
Thanks all for ur quick reply
i check condition in my code. and afte that i call the function del to delete the first node. But on display the elements of list it give garbage. Please suggest me where m going wrong.

Originally Posted by quzah

You can also check to see if loc == 1 before you even count them, because there's no reason to count them if you are just deleting the first one.

/*Delete the first node*/

Code:

void del(node**ptr)
{
     
     node *temp,*s;
     s = *ptr;
     temp = s;
     s=s->next;
     free(temp);     
}

Quzah.