Question

I am trying to make a function that sorts the linked list,which sorts the list by names.

struct student
 {
  char name[50];
  int roll_no;
  struct student *ptr_next;
 }*ptr_this,*ptr_first;/*ptr first points to first pointer */
void SortRecord(void)
{
 struct student *out,*in,*temp;
 for(out=ptr_first;out!=(struct student*)NULL;out=out->ptr_next)
 {
  for(in=out->ptr_next;out->ptr_next!=(struct student*)NULL;in=in->ptr_next)
  {
   if(strcmpi(out->name,in->name)<0)

  temp->ptr_next=in->ptr_next;
  in->ptr_next=out->ptr_next;
  out->ptr_next=temp->ptr_next;/*The program stops at this instant and does not proceed after this line*/
  }
 }
 printf("Records have been successfully sorted.");

I am stuck with 2 questions:
EDIT:
I understood that we only need to swap the pointers not the contents but my code still hangs at the swapping at the place mentioned above.

Answer 1

If you know that the result needs to be sorted, try sorting on list insertion instead. Depending on your design requirements, a heavy insert might be tolerated given that the “sorting” step becomes redundant. The concept might also be a bit easier to grasp.