Linked List

[kumar14878]

Hi!
I am trying to create a Linked List and inserting some numbers and displaying those numbers through display function.
But I am not able to get the appropriate result.
Hope someone will help.
thanks !.
Anil
Code which I am using.

#include<stdio.h>
#include<conio.h>
#include<malloc.h>
struct node
{
 int data;
 struct node *next;
}*temp;
void insert(struct node **p, int x)
{
 temp=*p;
  if(temp!=NULL)
  {
   temp=(struct node*)malloc(sizeof(struct node));
   temp->data=x;
   temp->next=NULL;
   *p=temp;
   }
  else
   {
    while(temp==NULL)
     {
      temp=temp->next;
      temp=(struct node*)malloc(sizeof(struct node));
      temp->data=x;
      temp->next=NULL;
     }
    return;
   }
}
void display(struct node *p)
{
 while(p!=NULL)
  {
   printf("%d",p->data);
   p=p->next;
  }
}
void main()
{
 temp=NULL;
 clrscr();
 insert(&temp,10);
 insert(&temp,20);
 insert(&temp,30);
 insert(&temp,40);
 display(temp);
 getch();
}

[Salem]

Perhaps if you tried to implement this without global variables called 'temp', you would get further.
Because the temp in your insert function which you trash is also the one storing the list in the first place.

> #include<conio.h>
Don't use this header - it's non-standard
If you want better ways to pause the program, see the FAQ

> #include<malloc.h>
malloc is in stdlib.h

> temp=(struct node*)malloc(sizeof(struct node));
Don't cast malloc in C (see the FAQ)

> void main()
main returns an int (see the FAQ (for the third time))

[0rion]

#include<malloc.h>

Use stdlib.h instead.

Hm, for your insertion function I'm not understanding how you are logically creating the list. Firstly,

 if(temp!=NULL)
  {
   temp=(struct node*)malloc(sizeof(struct node));
   temp->data=x;
   temp->next=NULL;
   *p=temp;
   }

I'm pretty sure you would want temp to be equivalent to NULL to insert at the head, not the other way around.

Likewise,

while(temp==NULL)
     {
      temp=temp->next;
      temp=(struct node*)malloc(sizeof(struct node));
      temp->data=x;
      temp->next=NULL;
     }

I'm pretty sure you want that until temp does NOT equal NULL then keep traversing through the list. Also you do NOT want to keep malloc'ing/creating new nodes for a traversal of a list.

You actually got some parts of it mixed up between the two, why are you doing:

temp = temp->next;

When temp is equal to NULL? So until you post back on you were really meant to do - it's pretty much of a mess. At least you got the right idea on your display function.

And one more thing, change void main() to int main(void).

Btw, you can also use the search button since there are countless threads on linked lists already - once you have a better idea on how they work, implement it yourself and if you have any errors then post back in this thread with the updated code.