Solved

How to find the bigger number.

Posted on 2006-07-04
5
202 Views
Last Modified: 2010-04-05
Hi...

This is easy i guess... I'm just not in thinging mode... right now and i want it fast.

So...
I have 120 integers and i want to find the 3 bigger numbers.
I need a smart way to do this with few lines.

Thanks in advance.
0
Comment
Question by:CodedK
  • 2
  • 2
5 Comments
 
LVL 17

Accepted Solution

by:
TheRealLoki earned 125 total points
ID: 17038552
to find the bigger of 2 numbers you can use
uses math;
i := max(j, k);

1 way for you to get the top 3 would be to have the numbers in a sorted list
eg.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, math,
  StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    numberlist: TList;
  end;

var
  Form1: TForm1;

function comparenumbers(Item1, Item2: Pointer): Integer;

implementation

{$R *.DFM}

function comparenumbers(Item1, Item2: Pointer): Integer;
    begin
        if Integer(Item1) < Integer(Item2) then result := -1
        else if Integer(Item1) > Integer(Item2) then result := 1
        else result := 0;
    end;

procedure TForm1.FormCreate(Sender: TObject);
    begin
        numberlist := TList.create;
// add some numbers
        numberlist.add(pointer(10));
        numberlist.add(pointer(8));
        numberlist.add(pointer(2));
        numberlist.add(pointer(7));
        numberlist.add(pointer(9));
        numberlist.add(pointer(1));
        numberlist.add(pointer(3));
    end;

procedure TForm1.FormDestroy(Sender: TObject);
    begin
        numberlist.Free;
    end;

procedure TForm1.Button1Click(Sender: TObject);
    var
        i: integer;
    begin
// make sure the numbers are sorted
        numberlist.Sort(comparenumbers);
// now grab the top 3 numbers and display them
        for i := (numberlist.count -1) downto (numberlist.count -3) do
          memo1.lines.add(inttostr( integer(numberlist[i])));
    end;

end.
0
 
LVL 17

Expert Comment

by:TheRealLoki
ID: 17038610
I know you said "a few lines" but really it's just "sort" then the for loop :-)
here's a way to do it assuming the get the numbers from somewhere else

procedure TForm1.Button2Click(Sender: TObject);
    var
        sl: TStringList;
        i, value: integer;
        s: string;
    begin
        sl := TStringlist.create;
        try
            sl.sorted := True;
            i := 0; // first index from whatever source of numbers you have
            while (i < numberlist.count) do  // last index from whatever source of numbers you have
            begin
// get the number using index i from your source numbers and convert it to a 10 length padded string
                SL.Add(Format('%10d', [ integer(numberlist[i]) ] )); // if you need bigger numbers, use a number > %10
                inc(i); // go to the next number
            end;
// now grab the top 3 numbers and display them
            for i := (sl.count -1) downto (sl.count -3) do
            begin
                value := StrToInt( sl[i] );
                memo1.lines.add(inttostr( value ));
            end;
        finally
            sl.free;
        end;
    end;
0
 
LVL 17

Assisted Solution

by:mokule
mokule earned 125 total points
ID: 17039472
Not so briliant but possibly faster method.

procedure TForm1.Button1Click(Sender: TObject);
const
  numcount = 100;
var
  intnum: array[0..numcount-1] of integer;
  i: integer;
  b1,b2,b3: integer;
begin
// fill in the array
  for i := 0 to numcount-1 do
    intnum[i] := random(1500);

  if intnum[0] > intnum[1] then
    begin
    b1 := intnum[0];
    b2 := intnum[1];
    end
  else
    begin
    b1 := intnum[1];
    b2 := intnum[0];
    end;
  b3 := intnum[2]-1;

  for i := 3 to numcount-1 do
    begin
    if intnum[i] > b3 then
      begin
      if intnum[i] > b2 then
        begin
        b3 := b2;
        if intnum[i] > b1 then
          begin
          b2 := b1;
          b1 := intnum[i];
          end
        else
          b2 := intnum[i];
        end
      else
        b3 := intnum[i];
      end;
    end;
  Memo1.lines.Add(IntToStr(b1));   // biggest number
  Memo1.lines.Add(IntToStr(b2));   // second biggest
  Memo1.lines.Add(IntToStr(b3));   // third bigest
end;
0
 
LVL 16

Author Comment

by:CodedK
ID: 17039804
Thank you both.

There is a small problem... I need to know the var that holds the bigger value...
Example : bigger 3 =>(a14, a87, a2)... not only the value.
---------------------------------------------

Since all the numbers will be finally loaded in a Chart maybe there is another way...

X axis represents the variable (a0, a1, a2...a120).

I've loaded all the vars in a TChart !
So with the command :

Chart1.SeriesList.Series[0].MaxYValue; .... i will find the bigger number.

Is there a command for this :
(For this Y which is the X) ???
(And with a for loop decreasing by 1 from the bigger y which is the next bigger y) ?

I hope i make sense.... Thank you very much :)
0
 
LVL 16

Author Comment

by:CodedK
ID: 17039859
Forget it... Thank you for your time :)
0

Featured Post

Is Your AD Toolbox Looking More Like a Toybox?

Managing Active Directory can get complicated.  Often, the native tools for managing AD are just not up to the task.  The largest Active Directory installations in the world have relied on one tool to manage their day-to-day administration tasks: Hyena. Start your trial today.

Question has a verified solution.

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

Suggested Solutions

Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
This Micro Tutorial demonstrates using Microsoft Excel pivot tables, how to reverse engineer competitors' marketing strategies through backlinks.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

770 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