Singly Linked List Question

[ecstasyaeternus]

Just starting to learn about linked lists, and I need to enter a last name and a GPA as a char and float respectively into a node, and then sort the list in numerical order of GPA (ascending or descending, doesn't matter).

Would I write this as:

	typedef struct Node;
	{
		char name[20];
		float gpa;
		Node *next;
	};

and then just do for loops to arrange them in order?

for( temp1 = head ; temp1!=NULL ; temp1 = temp1->next )
{
      for( temp2 = temp1->next ; temp2!=NULL ; temp2 = temp2->next )
      {
            if( temp1->data > temp2->data )
            {
                  temp = temp1->data;
                  temp1->data = temp2->data;
                  temp2->data = temp;
            }
      }
}

Thanks.

[onur]

You don't really want to sort singly linked lists.
If you need a singly linked list and need it sorted try it this way:
* create a vector out of your singly linked list
* sort the vector
* create a singly linked list out of the sorted vector

If you have really expensive to copy nodes consider using a vector that hold's just pointers to the data.

Have a look at this page:
* http://www.cplusplus.com/reference/algorithm/sort/

[Zhuge]

As for OP's actual question, your algorithm looks fine to me.

[ecstasyaeternus]

Thanks huge. Writing the structure like that though

		char name[20];
		float gpa;

will sort the GPA's and not the last names in ascii, right? I wasn't sure which should go first.

@onur thanks for the tip, I'll give it a gander after I finish some of this work that's piling up lol.

[D80DSL3A]

Another option is to swap the links instead of swapping the data.
This way, you don't have to swap each individual data element.

[onur]

If you prefer to stay with your version at least use the swap template:

for( temp1 = head ; temp1!=NULL ; temp1 = temp1->next )
{
      for( temp2 = temp1->next ; temp2!=NULL ; temp2 = temp2->next )
      {
            if( temp1->data > temp2->data )
            {

                  temp = temp1->data;
                  temp1->data = temp2->data;
                  temp2->data = temp;

                  std::swap(temp1->data, temp2->data)
            }
      }
}

Also note that the "data" used in the comparison (your key usde for sorting is gpa) is not the same as in the swap part (both name and gpa)!