Re: Link List - C# Discussion Boards

OK - if you wrote a linkedlist class, I guess this is homework ( you should never use your own container classes ). The easy way to do a sort, is to go through the list, and compare each pair of items, and swap them if they are in the wrong order. You need to do this n*n times, it's called a bubble sort. Another way to do it is to take each item and move it towards the front of the list until it's in the right place. This will be quicker.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

You can sort a linked list efficiently with a mergesort, Google for a solution.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

i google and found the following code

int[] mergeSort (int[] data) {
   if (data.Length == 1)
      return data;
   int middle = data.Length / 2;
   int[] left = mergeSort(subArray(data, 0, middle - 1));
   int[] right = mergeSort(subArray(data, middle, data.Length - 1));
   int[] result = new int[data.Length];
   int dPtr = 0;
   int lPtr = 0;
   int rPtr = 0;
   while (dPtr < data.Length) {
      if (lPtr == left.Length) {
         result[dPtr] = right[rPtr];
         rPtr++;         
      } else if (rPtr == right.Length) {
         result[dPtr] = left[lPtr];
         lPtr++;
      } else if (left[lPtr] < right[rPtr]) {
         result[dPtr] = left[lPtr];
         lPtr++;
      } else {
         result[dPtr] = right[rPtr];
         rPtr++;         
      }
      dPtr++;
   }
   return result;
}

The example takes in an integer, base on my code what should i take in? and if i wanan sort by name, how does the algorithm goes?

benjamin yap wrote:

The example takes in an integer, base on my code what should i take in? and if i wanan sort by name, how does the algorithm goes?

It doesn't make much sense to take a complete code and adjust it without knowing the algorithm that the basis of this algorithm. You should either take the time to understand how a merge sort (or any kind of sort algorithm) works, or otherwise you should really implement the most basic of all sorting algorithms, the bubble sort Christian mentioned.

modified 12-Sep-18 21:01pm.

It takes an int because it will sort the list from smallest to largest (or largest to smallest, i didn't actually look).

Your going to need to modify it for strings (if you want to do it by name). string.Compare(string, string) returns an int, less than zero means the first string is less than the second, 0 is equal, and greater than is larger.

So, string.Compare("cheesy", "bacon"); would return a number greater than 0 because 'c' comes after 'b' in the alphabet. I'm not sure if upper case letters make a difference so thats something you should check.

My current favourite word is: I'm starting to run out of fav. words!

-SK Genius

Game Programming articles start -here[^]-

benjamin yap wrote:
int[] mergeSort (int[] data)

Sorry, but that is for an array, not a linked list. Try again.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

So its

public LinkList MergeSort(LinkList data)

?

modified on Tuesday, June 24, 2008 12:44 AM

benjamin yap wrote:
public LinkList MergeSort(LinkList data)

Yes, it should look like that in the end. The code you pasted is for an int array. You could probably adjust that code to handle a generic linked list (an exercise for you, not me).

You could also just see what wikipedia say about the mergesort algorithm, and write your own from scratch. From what you can see, it is pretty simple.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

I realli cannot figure out. i tried this any keep getting error

Original Sample

  public static void qsort(char[] items) { 
    qs(items, 0, items.Length-1); 
  } 
 
  // A recursive version of Quicksort for characters. 
  static void qs(char[] items, int left, int right)  
  {  
    int i, j;  
    char x, y;  
  
    i = left; j = right;  
    x = items[(left+right)/2];  
  
    do {  
      while((items[i] < x) && (i < right)) i++;  
      while((x < items[j]) && (j > left)) j--;  
  
      if(i <= j) {  
        y = items[i];  
        items[i] = items[j];  
        items[j] = y;  
        i++; j--;  
      }  
    } while(i <= j);  
  
    if(left < j) qs(items, left, j);  
    if(i < right) qs(items, i, right);  
  } 
}

My code

public void qsort(LinkList list)
        {
            qs(list, 0, list.size - 1);
        }

        public void qs(LinkList list, int left, int right)
        {
            int i, j;
            LinkList
  
            i = left; j = right;
            x = list[(left+right)/2];

            do
            {
              while((list[i] < x) && (i < right)) i++;  
              while((x < list[j]) && (j > left)) j--;  
          
              if(i <= j) 
              {  
                y = list[i];  
                list[i] = list[j];  
                list[j] = y;  
                i++; j--;  
              }  
            } while(i <= j);  
  
            if(left < j) qs(list, left, j);  
            if(i < right) qs(list, i, right);  
  }

I realli dont know what to change...because their example is using a char array. but for my case, i am using an object Entity which have 3 attributes

Hi, i have created my GUI for a inventory system.

I want to store the data entered in the form to database or xml or flatfile.

which is recommended?

my design of the program is using MDIform.. how should i store the connection string or etc etc?

benjamin yap wrote:
which is recommended?

For an inventory ? A real SQL database, for sure. Unlikely for that to be small enough to be using XML or some other flat file

benjamin yap wrote:
how should i store the connection string or etc etc?

in the app config

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

what do you mean app config? how can i find that? or do i have to create my self

your project has a file called app.config in it. It gets turned into *yourappname*.exe.config at compile time. You put settings stuff in there.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

i cant find it.

at the solution explorer it have

Solution "windowsapplication4" (1 project)
- WindowsApplication4
- - Properties
- - Reference
- - Form1.cs
- - Program.cs
- - Settings.cs

Well, you can add one if you don't see it. I always see them in my projects, tho.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Issit

Name | Type | Scope | Value
setting string User

so i just change the string to (connection String) and set the value there?

how does the value look like?
Issit when i compile, i don have to declare the connection string again?

http://www.ajaxline.com/node/258[^]

I recommend reading the article I link to in my sig.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

I suggest doing some reading. Yes, the point of a config file is that you store values which can be changed by the end user, but you don't need to enter them again.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Add new item to your project. Select Application Configuration File. It is not added automatically in VS2003.

i am using Microsot Visual Studio 2005

When i select add new Item, i have SQL Database file and Settings File.

I selected settings file

Well, is the project Windows Application project?

It should be Application Configuration or something similar (don't have VS now).

Hello all,

I'm trying to change an attribute in an XML document based on some criteria,
I'm using C#, For example I need to do a "search" based on a person's user id,
the user id is an attribute of a node name student.

if the userid matches a text box I then need to change the Grade attribute of the student.

for example, my xml document looks like this


<Students>
<Student userID="567" Registration="Reg268" Grade="A" Subject="Math"/>
<Student userID="345" Registration="Reg951" Grade="B" Subject="Science"/>
<Student userID="475" Registration="Reg195" Grade="B" Subject="Science"/>
</Students>

I want to 'search' for student 345 and then change the Grade to an 'A'

Any help would be greatly appreciated.
JC

You can select a node in an XmlDocument using Xpath and then use the Attributes collection to access/change an attribute.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Thank you for your help..

How I got it to work.
created a new element,
assigned the old node to a new node specific to my search criteria

newnode = root.SelectSingleNode("Students/Student/[@userid='" + loginform.userid + "']");

I then created a new attribute
and used the append function to add the newly created attribute as the last attribute.

saved the document... and it worked..

hope this help someone....

thanks again.
JC

how to create a C# program that directly controls the activity of the computer such as creating a folder, deleting a file etc. Smile | :)