Lazarus

Programming => General => Topic started by: garandr on December 01, 2020, 06:04:08 pm

Title: Find the sum of elements belonging to the interval from A to B
Post by: garandr on December 01, 2020, 06:04:08 pm
Code: Pascal  [Select][+][-]
  1. unit Unit3;
  2.  
  3. {$mode objfpc}{$H+}
  4.  
  5. interface
  6.  
  7. uses
  8.   Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls, Grids;
  9.  
  10. type
  11.  
  12.   { TForm3 }
  13.  
  14.   TForm3 = class(TForm)
  15.     Button1: TButton;
  16.     Edit1: TEdit;
  17.     Edit2: TEdit;
  18.     Edit3: TEdit;
  19.     Label1: TLabel;
  20.     StringGrid1: TStringGrid;
  21.     procedure Button1Click(Sender: TObject);
  22.   private
  23.  
  24.   public
  25.  
  26.   end;
  27.  
  28. var      C : array[1..10] of integer;
  29.          i,kol,sum:integer; A,B:integer;
  30. Form3: TForm3;
  31.  
  32. implementation
  33.  
  34. {$R *.lfm}
  35.  
  36. { TForm3 }
  37.  
  38. procedure TForm3.Button1Click(Sender: TObject);
  39. begin
  40.        A:=StrToInt(Edit1.Text);
  41.        B:=StrToInt(Edit2.Text);
  42.        sum := 0;
  43.        kol:=0;
  44.        for i := 1 to 10 do
  45.  begin
  46.        C[i] := random (100);
  47.        StringGrid1.Cells[i-1,0] := IntToStr(C[i]);
  48.        if (A <= C[i]) and (B>= C[i]) then inc (kol);
  49.  end;
  50.        Edit3.Text:=( IntToStr(kol)+ ' element between '+IntToStr(A)+' and '+IntToStr(B) );
  51.        if (C[i] >= A) and (C[i] <= B) then
  52.        sum := sum + C[i] ;
  53.        if sum > 0 then
  54.             Edit3.Text:=IntToStr(sum);
  55. end;
  56.  
  57.  
  58.  
  59.  
  60. end.
  61.              
  62.  
  63.  
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: bytebites on December 01, 2020, 06:30:51 pm
Format your code first. Random indentation is mess.
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: lucamar on December 01, 2020, 06:38:55 pm
Other than the hideous indentation, that you forgot to (re)initialize kol, and the unnecessary repeated check, what's the problem?
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: garandr on December 01, 2020, 07:00:09 pm
Quote from: bytebites on December 01, 2020, 06:30:51 pm
Format your code first. Random indentation is mess.
Ok :-\
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: garandr on December 01, 2020, 07:15:57 pm
Quote from: lucamar on December 01, 2020, 06:38:55 pm
Other than the hideous indentation, that you forgot to (re)initialize kol, and the unnecessary repeated check, what's the problem?
What's up with kol?
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: lucamar on December 01, 2020, 07:44:34 pm
Quote from: garandr on December 01, 2020, 07:15:57 pm
What's up with kol?

Nothing, sorry. Looking more closely I see it is initialized right after sum; don't know how I missed that ... :-[

The question still holds, though, what's the problem?
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: garandr on December 01, 2020, 07:53:41 pm
Quote from: lucamar on December 01, 2020, 07:44:34 pm
Quote from: garandr on December 01, 2020, 07:15:57 pm
What's up with kol?

Nothing, sorry. Looking more closely I see it is initialized right after sum; don't know how I missed that ... :-[

The question still holds, though, what's the problem?

Elements between A and B are indicated incorrectly, and the amount is not considered
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: wp on December 01, 2020, 08:37:56 pm
Let me fix the indentation to see what's going on:

Code: Pascal  [Select][+][-]
  1. procedure TForm3.Button1Click(Sender: TObject);
  2. begin
  3.   A:=StrToInt(Edit1.Text);
  4.   B:=StrToInt(Edit2.Text);
  5.   sum := 0;
  6.   kol:=0;
  7.   for i := 1 to 10 do
  8.   begin
  9.     C[i] := random (100);
  10.     StringGrid1.Cells[i-1,0] := IntToStr(C[i]);
  11.     if (A <= C[i]) and (B>= C[i]) then inc (kol);
  12.   end;      
  13.   Edit3.Text:=( IntToStr(kol)+ ' element between '+IntToStr(A)+' and '+IntToStr(B) );
  14.   if (C[i] >= A) and (C[i] <= B) then
  15.     sum := sum + C[i] ;
  16.   if sum > 0 then
  17.     Edit3.Text:=IntToStr(sum);
  18. end;

By the indentation of the begin/end pair you can see what is included inside the "for" loop. What follows the "end" is outside the loop. But you see that there is "i code" outside the loop: "if C[ i] > = >"... -- I guess this must be inside the loop because the loop variable is well-defined only inside the loop.
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: Paolo on December 01, 2020, 08:54:15 pm
it should be: (you also forget to join the two times call to Edit3.text, if sum was > 0 in your code you will never see the first string "..element between..")

Code: Pascal  [Select][+][-]
  1. procedure TForm3.Button1Click(Sender: TObject);
  2. begin
  3.   A:=StrToInt(Edit1.Text);
  4.   B:=StrToInt(Edit2.Text);
  5.   sum := 0;
  6.   kol:=0;
  7.   for i := 1 to 10 do
  8.   begin
  9.     C[i] := random (100);
  10.     StringGrid1.Cells[i-1,0] := IntToStr(C[i]);
  11.     if (A <= C[i]) and (B>= C[i]) then begin
  12.       inc (kol);
  13.       sum := sum + C[i] ;
  14.     end;
  15.   end;      
  16.   Edit3.Text:=( IntToStr(kol)+ ' element between '+IntToStr(A)+' and '+IntToStr(B) );
  17.   if sum > 0 then
  18.     Edit3.Text:=Edit3.Text+', and the sum is '+IntToStr(sum);
  19. end;
Title: Re: Find the sum of elements belonging to the interval from A to B
Post by: Thaddy on December 02, 2020, 09:20:40 pm
Quote from: garandr on December 01, 2020, 07:15:57 pm
Quote from: lucamar on December 01, 2020, 06:38:55 pm
Other than the hideous indentation, that you forgot to (re)initialize kol, and the unnecessary repeated check, what's the problem?
What's up with kol?
Besides that kol here means something different from the below remarks:
Dunno. I lost a bit of interest. Will contact Vladimir et. al. Will have to do that for Christmas anyway...
But it still works both for 32/64 bit Windows - including wince - and it is stable. (the FPC part, don't know about the mirror components since I rarely used them.)

Also note you can NOT mix Kol with rtl/fcl/lcl. It is a complete framework. You will loose its size benefits if you do and run into problems
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