Thread: Linked List

Originally Posted by kyel_dai92

I am currently learning linked list and our proff gave us this code but I can't seem to compile it, what's the problem here?

Code:

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

struct node
{
       int x;
       struct node *next;
       };
       
       int main()
       {
          struct node *root;
          struct node *conductor;
          conductor=root;
          root = malloc(sizeof(struct node));
          root->next=0;
          root->x=5;
       
           while(conductor->next!=0);
           {
              printf("%d",conductor->x);
              conductor=conductor->next;
                                       
                                       }

           system("pause");
           }

I can't seem to print the value of x :| why is it like that?


(EDIT Done with the tagging )

Take a close look at the first couple of pointers before malloc()... conductor=root ... what is the value of root at that point?

If this is unmodified code from your instructor, you need to ask him if the bugs in it were deliberate...

what if I want to add another block? or node?

Originally Posted by kyel_dai92

what if I want to add another block? or node?

Well, first you need to fix the bugs in what you've got.

Originally Posted by CommonTater

Well, first you need to fix the bugs in what you've got.

I've fixed it here it is

Code:

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

struct node
{
       int x;
       struct node *next;
       };
       
       int main()
       {
          struct node *root;
          struct node *conductor;
          root = malloc(sizeof(struct node));
          conductor=root;
          root->next=0;
          root->x=5;
       
           while(conductor->next!=NULL);
           {
              printf("%d",conductor->x);
              conductor=conductor->next;
                                       
                                       }
           
           system("pause");
           }

now how to add anotehr value and block? so that It will print 2 then (the value i inserted )

I take it you're on like day 1 of this part of your course... (which is fine)

Basically you need to create a new struct in memory and get a pointer to it.
Then you need to insert whatever data
Finally you need to add it to the end of your list by modifying the next pointer in your previous last record.

Originally Posted by CommonTater

I take it you're on like day 1 of this part of your course... (which is fine)

Basically you need to create a new struct in memory and get a pointer to it.
Then you need to insert whatever data
Finally you need to add it to the end of your list by modifying the next pointer in your previous last record.

How am I going to do it? my knowledge about linked list is only 10% or even lower how do i do that? I am not gonna modify, I am just gonna add, they are gonna show an output of 5 then 2.

In a linked list each record provides you with a pointer to the next record.

1.next -> 2.next -> 3

So if you want to add #4 you you have to make #3 point to the new entry...

1.nest -> 2.next -> 3.next -> 4

That means modifying the "next" pointer in your last record to point to the new one

I'd suggest you give this a read...
Cprogramming.com Tutorial: Linked Lists

so it'll be like this?

Code:

struct node *root;
          struct node *conductor;
          conductor=root;
          root = malloc(sizeof(struct node));
          root->next=0;
          root->x=5;
root->next-next=malloc(sizeof(struct node));
root->x=4;

like this?

It's still wrong! You've ignored CommonTater's question:

Take a close look at the first couple of pointers before malloc()... conductor=root ... what is the value of root at that point?

which is extremely important. Don't put the cart before the horse looking to add stuff to what's currently quite broken.

There are a bazillion tutorials and explanations of linked lists on the net. Surely you can Google some up and try to get a better understanding of them?

Originally Posted by rags_to_riches

It's still wrong! You've ignored CommonTater's question:



which is extremely important. Don't put the cart before the horse looking to add stuff to what's currently quite broken.

There are a bazillion tutorials and explanations of linked lists on the net. Surely you can Google some up and try to get a better understanding of them?

well I didn't ignored, I actually read it and used it for my code

Bump