I'm implementing a doubly linklist in c++.im trying to add a node at the beginning of the doubly linklist,but

the method doesnt work.im compiling in Turbo c++.


here is the code :


void linklist :: add_at_first()


{ node *temp;


temp = new node();


temp -%26gt;prev=temp -%26gt;next=NULL;


cout %26lt;%26lt;"Please Enter A Number :"%26lt;%26lt; endl;


cin %26gt;%26gt; temp -%26gt; num;





if(first ==last==NULL)// if the list is empty


{ first = last=temp;


}


else


{


temp -%26gt; next = first;


first = temp;


}


}


when i use set watch to see the values of the elements,it says :"undefined symbol "the item i selected.""

I'm implementing a doubly linklist in c++.im trying to add a node at the beginning of the doubly linklist,but
shouldn't the last part of your code look more like...





...


else


{


first-%26gt;prev=temp;


temp-%26gt;next=first;


first=temp;


}


}





You did say doubly linked correct? The way you have it now, you correctly set temp-%26gt;next to point to the first node but you never tell the first node to point back to the newly created temp.

forsythia