Linked list help!

>> is there anyway to modify it ?

What do you mean ? How do you want to modify it ?

linked_list_new creates a new node - how do you want to insert a node if you don't create it ?

05.15.2008 at 12:12AM PDT, ID: 21571194

Rank: Sage

Ah, sorry, I misinterpreted your code.

linked_list_new creates a new (empty) list. Why do you need to create a new list when you want to add a node ?

A node should be added to an existing list (which should be passed as the first parameter to the add function).

05.15.2008 at 12:14AM PDT, ID: 21571201

Rank: Sage

You can make the linked_list variable a global but then
1. You will have to maintain a global for every linked list that you wish to create
2. You will end up with more globals - namespace pollution etc.

Is there a specific reason why you wish to change it? I would recommend sticking with it ... This is proper uise of functions and would get you comfortable with pointer parameter passing over a period of time.

Accepted Solution

05.15.2008 at 12:17AM PDT, ID: 21571220

so if i have 3 linked list, i nid to pass them all into one function that makes use of all 3? :o

05.15.2008 at 12:19AM PDT, ID: 21571237

Rank: Sage

No ... you make another function call

05.15.2008 at 12:20AM PDT, ID: 21571238

lucky_james:

you can mdify the signature to
struct linked_list* linked_list_new( node* Behind /*= NULL*/, node* Ahead /*= NULL*/)

and inside it :
1. allocate the memory for one 'node' and not the list.
2. wire this new node onto desired place.
a. if behind node* is given, then you need to add this new node as the next node to the 'behind' node.
b. if Ahead node is provided, then you need to add 'Ahead' node as next node to this new node.
dont put
if a
else if b

put
if a
if b
becoz both conditions can coexist.

05.15.2008 at 12:21AM PDT, ID: 21571242

Rank: Sage

linked_list_add( list1, 5);
linked_list_add( list2, 15);
linked_list_add( list3, 101);

05.15.2008 at 12:27AM PDT, ID: 21571274

i think my question is misinterpretated.

lets say i have 3 linked list and i create it when program starts
int main () {
struct list1 *one;
struct list2 *two;
struct list3 *three;
one = linked_list1_new();
two= linked_list2_new();
three= linked_list3_new();
generate_data(one, two, three, string[]);
}

05.15.2008 at 12:32AM PDT, ID: 21571297

Rank: Sage

Assuming from name that generate_data is supposed to generate data, there is no need to pass the lists to it. If you were to add another list, why would it affect the data generator?

Also assuming that string is a parameter used to generate data and same data would be added to all 3 lists, your calling code should look like this

int data = generate_data(my_string);
linked_list_add( one, data);
linked_list_add( two, data);
linked_list_add( three, data);

An even more elegant way would be to keep all three lists in another list/array and iterate over them to add the data.

05.15.2008 at 12:35AM PDT, ID: 21571311

Rank: Sage

What does generate_data do ?

05.15.2008 at 12:38AM PDT, ID: 21571318

well because i have to do some processing on the string, then assign them to different linked list for different conditions. dats why :(

05.15.2008 at 12:39AM PDT, ID: 21571327

Rank: Sage

Can you provide more details? It should be possible to isolate data processing from details of data storage.

05.15.2008 at 12:39AM PDT, ID: 21571328

generate data reads a line of text and put them in their respective linked list.

e.g employee xx xxx goes into employee list
user xx xx goes into user list
and so on

05.15.2008 at 12:44AM PDT, ID: 21571339

Rank: Sage

generate_data can return a struct employee that has values filled into fields
your add_data will accept pointer to struct employee and all lists. This function will add data to respective lists. If you were to add fields, then it would affect both generate_data and add_data. If you were to add only a list, it would affect only add_data.
If you need to add different data to different lists then either you need to make separate calls to same add_data function (the approach I recommended earlier) or you need to have a function that accepts multiple lists as arguments and adds data to appropriate lists. Which one to use depends on your requirements.

05.15.2008 at 12:55AM PDT, ID: 21571387

Rank: Sage