Solved

'InsertionSort'ing a linked list

Posted on 1998-10-23
7
238 Views
Last Modified: 2011-09-20
Does anyone have code for Sorting a linked list using InsertionSort? Sorting by file size, date/time and then if necessary ID.  Without allocating any additional memory.  URGENT.  Bonus: if you determine the theoretical runtime.
0
Comment
Question by:stuckart
7 Comments
 
LVL 2

Expert Comment

by:kellyjj
ID: 1253772
sounds like homework to  me. You should try this yourself and then  ask on the parts you are having probs with.
0
 

Author Comment

by:stuckart
ID: 1253773
This is not a homework question.  I am trying to teach myself.  It is easiest for me to learn by example.  The part that is hardest for me is the swapping of the pointers.
0
 
LVL 84

Expert Comment

by:ozo
ID: 1253774
what have you tried?
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:stuckart
ID: 1253775
Have in mind that I don't quite understand pointers that well.

void InsertionSort (Node *pHead)
  {
    Node *pCur = *pHead, *pTemp = *pHead;
    while( pCur)      <------   don't know what to put here, want to check if pCur is valid
      {
         pCur  =  pCur->pNext;
         while( pTemp->value > pCur->value)
            {
              swap them here.  Not sure how to move the pointers to do this.
            }
      }
}

In my Data structure I have   File, Date, ID  they are incremented by 1.
I'll put the exact code here, once my e-mail provider gets back online.  Figures huh.

thanks,
Jerry

0
 
LVL 12

Accepted Solution

by:
rwilson032697 earned 100 total points
ID: 1253776
Your code is pretty much there. The while (pCur) is fine as long as pCur is set to NULL when it runs into the end of the list.

Instead of the inner while do this for the insertion:

        if( pTemp->value > pCur->value)
        {
           pTemp->nNext = pCur->pNext;
           pCur->pNext = pTemp;
        }

In terms of theoretical runtime this will be O(n squared). If you had used an array it would have been O(n log n).

To swap two pointers do this:

Node *SwapTemp = SecondNode;
SecondNode = FirstNode;
FirstNode = SwapTemp;

Cheers,

Raymond.
0
 
LVL 12

Expert Comment

by:rwilson032697
ID: 1253777
Just a wee note: The O(n log n) for an array assumes you use a binary search to locate the insertion positon - the overhead of the actual array insertion operation is ignored.
0
 

Author Comment

by:stuckart
ID: 1253778
Thank you very much.  I actually had it almost exactly like you said, but I didn't have the *'s in the right place.  Thank you again,

Jerry Stuckart
stuckart@csd.uwm.edu

0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Inorder binary search tree 5 179
negation in C function 14 171
How to jump to matching brace in eclipse editor ? 1 355
Why isn't object file created? 6 93
Windows programmers of the C/C++ variety, how many of you realise that since Window 9x Microsoft has been lying to you about what constitutes Unicode (http://en.wikipedia.org/wiki/Unicode)? They will have you believe that Unicode requires you to use…
Examines three attack vectors, specifically, the different types of malware used in malicious attacks, web application attacks, and finally, network based attacks.  Concludes by examining the means of securing and protecting critical systems and inf…
The goal of this video is to provide viewers with basic examples to understand opening and reading files in the C programming language.
The goal of this video is to provide viewers with basic examples to understand how to create, access, and change arrays in the C programming language.

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question