(Integer-) Comparison Function buggy!?

[CurryWurst]

Does anyone ever attempt to compare two strings represting integer values?

Code: [Select]

procedure ActivateServer();
var
  Str1, Str2: string;
begin
  Str1:= '28950';
  Str2:= '500';
  if (Str1 > Str2) then
  begin
    WriteLn(Str1 + ' is greater than ' + Str2);
  end else
  begin
     WriteLn(Str2 + ' is greater than ' + Str1 + ', really??');
  end;
end;

.... the result is dubious!!

C++ examples like this work well. I don't know how the Soldat scripting engine compares strings,
but this instance raises doubts about it.

[EnEsCe]

Its not a bug, it was never intended for strings to be compared like that. It's a terrible way to code and unoptimal. Pascal is not C++.

[CurryWurst]

Sure, Pascal is not C++ but something like this could be really useful especially if you try to implement sort algorithms.
Owing to this problem my QuickSort procedures are divided into two seperate ones.

I thought about filling the compare string which is less in length with zeros, so both strings are equal in length.
Unfortunately this did not work out.

It's up to you

[iDante]

strtoint...

Or you could write a quick thing to compare them based on the actual chars in the string (would be recursive but easy to do).

[CurryWurst]

strtoint...

Owing to this problem my QuickSort procedures are divided into two seperate ones.

*One is based on StrToInt, the other on just on string compare.

Or you could write a quick thing to compare them based on the actual chars in the string (would be reflexive but easy to do).

Nice idea, I may pursue it

[CurryWurst]

I thought about filling the compare string which is less in length with zeros, so both strings are equal in length.

o.O Sorry, I have to redefine my statement ...

Code: [Select]

function GetLongestString(var Str: array of string): integer;
var
  i: integer;
begin
   for i:= 0 to ArrayHigh(Str) do
   begin
     if (length(Str[i]) > length(Str[Result])) then
     begin
       Result:= i;
     end;
   end;
end;

function FillWith(const Filler: char; Amount: integer): string;
var
  i: integer;
begin
  for i:= 1 to Amount do
  begin
    Result:= Filler + Result;
  end;
end;

procedure SelectionSort(var Field: array of string; Left, Right: integer);
var
  Buffer: string;
  i, j, m: integer;
begin
  i:= 1;
  m:= GetLongestString(Field);
  while (j < Right) do
  begin
    Field[j]:= FillWith('0', m - length(Field[j]));
    Field[j + i]:= FillWith('0', m - length(Field[j + i]));
    if (Field[j] > Field[j + i]) then
    begin
      Buffer:= Field[j];
      Field[j]:= Field[j + i];
      Field[j + i]:= Buffer;
    end;
    if (j + i < Right) then
    begin
      Inc(i, 1);
    end else
    begin
      i:= 1;
      Inc(j, 1);
    end;
  end;
end;

It's working but it's not supposed to because there are two lines of weird code:

Field[j]:= FillWith('0', m - length(Field[j]));
Field[j + i]:= FillWith('0', m - length(Field[j + i]));

After calling FillWith() two times both string must contain zeros because I did not add their old content Field[j] and Field[j + i] to them,
but they contain zeros + old content

Any explanations?

[SpiltCoffee]

If you remove 'm -', does the whole variable get filled?

[CurryWurst]

It gets filled to the amount of the variable length * 2. Assuming that there is string containing "225" as value.
Once the function FillWith() is called it contains "000225".

[danmer]

if Field[] is a tstringarray, you gotta setlength it to 0 and back if you want to reset the values. I had this bug with using xsplit - it kept the old values and added the ones i wanted to assign there to them...

[CurryWurst]

Hmm Field[] is string array and I did not use xsplit

[CurryWurst]

Seriously, EnEsCe how can this script work?
It contains more than only one bug ....

Script

Code: [Select]

function GetMaxStringSize(const Field1: array of string): integer;
var
  i: integer;
begin
   for i:= 0 to ArrayHigh(Field1) do
   begin
     if (length(Field1[i]) > Result) then
     begin
       Result:= length(Field1[i]);
     end;
   end;
end;

function FillWith(const Filler: char; Amount: integer): string;
var
  i: integer;
begin
  for i:= 1 to Amount do
  begin
    Result:= Filler + Result;
  end;
end;

procedure SelectionSort(const Bunch: array of string; Left, Right: integer);
var
  Buffer: string;
  i, j, m: integer;
begin
  i:= 1;
  m:= GetMaxStringSize(Bunch);
  while (j < Right) do
  begin
    Bunch[j]:= FillWith('0', m - length(Bunch[j]));
    Bunch[j + i]:= FillWith('0', m - length(Bunch[j + i]));
    if (Bunch[j] > Bunch[j + i]) then
    begin
      Buffer:= Bunch[j];
      Bunch[j]:= Bunch[j + i];
      Bunch[j + i]:= Buffer;
    end;
    if (j + i < Right) then
    begin
      Inc(i, 1);
    end else
    begin
      i:= 1;
      Inc(j, 1);
    end;
  end;
end;

function IXSplit(const SOURCE: string; Delimiter: string): array of string;
var
  i, x, d: integer;
  s, b: string;
begin
  d:= length(Delimiter);
  i:= 1;
  SetArrayLength(Result, 0);
  while (i <= length(SOURCE)) do
  begin
    s:= Copy(SOURCE, i, d);
    if (s = Delimiter) then
    begin
      SetArrayLength(Result, x + 1);
      Result[x]:= b;
      Inc(i, d);
      Inc(x, 1);
      b:= '';
    end else
    begin       
      b:= b + Copy(s, 1, 1);
      Inc(i, 1);
    end;
  end;
  if (b <> '') then
  begin
    SetArrayLength(Result, x + 1);
    Result[x]:= b;
  end;
end;

procedure ActivateServer();
var
 i: integer;
 a: array of string;
begin
  a:= IXSplit(ReadFile('compare.txt'), #13#10);
  SelectionSort(a, 0, GetArrayLength(a) - 1);
  for i:= 0 to ArrayHigh(a) do
  begin
    WriteLn(a[i]);
  end;
end;

Compare.txt

Code: [Select]

200
4400
30
0
1
11
-10
-2
99000
4555
2
412987231
5621

I guess my PC has got a virus

[CurryWurst]

It seems that nobody tried to deal with my problem.
So, I decided to develop my own working function (Click)

It even sorts an array of string representing integer values