Thread: Insertion in linked list

I am unable to insert data in a linked lists.
Show function is not working.
insert

Code:

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

   typedef struct node{
   int data;
   struct node *next;
   }
   Node;
   Node *sptr;
   Node *head=NULL;
   
   void show();
   void ins(int key);
   
   int main()
   {
   int i,item;
   for(i=0;i<=5;i++)
      {
   printf("Enter number\n"); // Inserting 6 elements in list
   scanf("%d",&item);
   ins(item);                    
      }
   show();                       //To show the data in linked list
   return 0; 
   }
   void ins(int key)
    {
    Node *ptr=NULL;
    ptr=(Node*)malloc(sizeof(Node));
    ptr->data=key;
    if(head==NULL)
        {
    head=ptr;
    ptr->next=NULL;
        }
    else
        {
    ptr->next=head;
    head=ptr;
        }
    }
    
    void show()
    {
    while(sptr->next!=NULL)
      {
    printf("%d\n",sptr->data);
      }
    }

Please indent your code properly. You should also explain how does the code not work.

Well, you did not assign to sptr in your show function.

That makes it even worse. Your show function should look like this:

Code:

void show(const Node *node)
{
    while (node != NULL)
    {
        printf("%d\n", node->data);
        node = node->next;
    }
}

Notice that I declared a parameter named node of type const Node*. The const is there because when you're displaying something, you typically don't need to change it, i.e., it is constant in that context. Then, I loop over the nodes starting from that node. Notice that I assign to node within the loop: that's how we get from the current node to the next node. This function could be called like this:

Code:

show(head);

head should be a local variable too.

Oh, and notice that I indented the code properly: the body of the function is indented by one level, then the body of the while loop indented by yet another level. This way, we can easily see where they start and end.

I'm so sorry to hear that. Perhaps you should post your current code and explain how does it not work. Otherwise, I will only be able to help you after I have acquired mind reading powers over the vast distances that separate us, and that could very well be never.