i need entire code of using "heap sort" to sort several integers.Must
using visual interface.(Form1: enter values in the box, once a
integer. then press "sort" botton; Form 2:show the sorted values, and
let user to choose repeat the program or exit)

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Request for Question Clarification by joseleon-ga on 01 Dec 2002 07:39 PST

Hello, aprilchiang:
  Because you want visual interface, for which compiler and OS do you
want this code? C++ Builder is ok for you?

Regards.

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Clarification of Question by aprilchiang-ga on 01 Dec 2002 09:13 PST

i just want it could run on windows 98 or xp. i usually write the code
with Broland C++ builder. it will be great if you use C++..
thanks a lot

Hello:
  Here is the source code you requested, I used C++ Builder 6, but you
must have no problems to use the non-visual C++ code in another
compiler. You can download the complete project including forms and
the precompiled exe from this url:
  
  http://www.xpde.com/Heap.zip
  
And below is the source code:

Unit1.h
//---------------------------------------------------------------------------

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>

///---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:	// IDE-managed Components
    TButton *btnSort;
    TListBox *lbItems;
    TButton *btnAdd;
    TButton *btnClear;
    TButton *btnExit;
    void __fastcall btnSortClick(TObject *Sender);
    void __fastcall btnClearClick(TObject *Sender);
    void __fastcall btnAddClick(TObject *Sender);
    void __fastcall btnExitClick(TObject *Sender);
private:	// User declarations
    int a[255];     //255 elements max
    int heapsize;
    int elements;
public:		// User declarations
    __fastcall TForm1(TComponent* Owner);
    void heapsort();
    void buildheap();
    void heapify(int i);
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif
  
  
  
  
Unit1.cpp  
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
#include "Unit2.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}
//---------------------------------------------------------------------------

void TForm1::heapsort()
{
    int t;
    int k;

    buildheap();

    for (k=elements;k>=1;k--)
    {
        t=a[k];
        a[k]=a[0];
        a[0]=t;
        heapsize--;
        heapify(0);
    }
}

void TForm1::buildheap()
{
    int j;
    heapsize=elements+1;
    for (j=((elements+1) / 2) - 1;j>=0;j--) heapify(j);
}

void TForm1::heapify(int i)
{
    int l;
    int r;
    int max;
    int t;

    l=2*i+1;
    r=2*i+2;

    if ((l<heapsize) && (a[l]>a[i])) max=l;
    else max=i;

    if ((r<heapsize) && (a[r]>a[max])) max=r;

    if (max!=i)
    {
        t=a[max];
        a[max]=a[i];
        a[i]=t;
        heapify(max);
    }
}

void __fastcall TForm1::btnSortClick(TObject *Sender)
{
    int k;
    elements=lbItems->Items->Count-1;

    for (k=0;k<=elements;k++) a[k]=lbItems->Items->operator
[](k).ToInt();
    heapsort();

    Form2->lbSorted->Items->Clear();
    for (k=0;k<=elements;k++)
    {
        Form2->lbSorted->Items->Add(AnsiString(a[k]));
    }

    Form2->ShowModal();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::btnClearClick(TObject *Sender)
{
    lbItems->Items->Clear();
}
//---------------------------------------------------------------------------
void __fastcall TForm1::btnAddClick(TObject *Sender)
{
    AnsiString value;
    InputQuery("Add value","Value",value);
    lbItems->Items->Add(value);
}
//---------------------------------------------------------------------------
void __fastcall TForm1::btnExitClick(TObject *Sender)
{
    Close();
}
//---------------------------------------------------------------------------
  
  
  
The another form is just to hold the sorted results, no code involved,
download the zip mentioned earlier to get the full working project. I
hope this is what you were looking for and don't hesitate to request
for any clarification.

No url references for this answer because is just an implementation of
a well-known algorithm.

Regards.

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Request for Answer Clarification by aprilchiang-ga on 02 Dec 2002 17:49 PST

hello jpseleon,

thanks a lot for your help. i have copied the code into my bourland
C++ 5 and recomplier it. it shows :
"[C++ Error] Unit1.cpp[76]:E2316 'operator[]' is not a member of
'TStrings'" with the line:
a[k]=lbItems->Items->operator[](k).ToInt();
i don't know how to fix it.. is it because the different edition of
the compiler?
thanks for your help again...

---

Clarification of Answer by joseleon-ga on 03 Dec 2002 05:53 PST

Hello:
 Sorry, I used C++Builder 6 with the new extensions, you can just
change that line to this:

    for (k=0;k<=elements;k++) a[k]=lbItems->Items->Strings[k].ToInt();

It's better you download the full code, from the previous url instead
of copying and pasting, because you will need the Form resources.

Any other problem? don't hesitate to ask ;-)

Regards.

thanks a lot