Janilabo | TIAByRange(2bit)

const
  RANGE1_START = -999999;
  RANGE1_FINISH = 999999;

function TIAByRange(aStart, aFinish: Integer): TIntArray;
var
  i: Integer;
begin
  if (aStart <> aFinish) then
  begin
    SetLength(Result, (IAbs(aStart - aFinish) + 1));
    if (aStart > aFinish) then
      for i := aStart downto aFinish do
        Result[(aStart - i)] := i
    else
      for i := aStart to aFinish do
        Result[(i - aStart)] := i;
  end else
    Result := [aStart];
end;

function TIAByRange2bit(aStart, aFinish: Integer): TIntArray;
var
  g, l, i: Integer;
  r: Boolean;
begin
  if (aStart <> aFinish) then
  begin
    l := (IAbs(aStart - aFinish) + 1);
    SetLength(Result, l);
    g := ((l - 1) div 2);
    r := (aStart < aFinish);
    case r of
      True:
      begin
        for i := 0 to g do
        begin
          Result[i] := (aStart + i);
          Result[((l - 1) - i)] := (aFinish - i);
        end;
        if ((l mod 2) <> 0) then
          Result[i] := (aStart + i);
      end;
      False:
      begin
        for i := 0 to g do
        begin
          Result[i] := (aStart - i);
          Result[((l - 1) - i)] := (aFinish + i);
        end;
        if ((l mod 2) <> 0) then
          Result[i] := (aStart - i);
      end;
    end;
  end else
    Result := [aStart];
end;

const
  RANGE2_START = RANGE1_FINISH;
  RANGE2_FINISH = RANGE1_START;

var
  t: Integer;
  TIA: TIntArray;

begin
  ClearDebug;
  t := GetSystemTime;
  TIA := TIAByRange(RANGE1_START, RANGE1_FINISH);
  WriteLn('TIAByRange(' + IntToStr(RANGE1_START) + ', ' + IntToStr(RANGE1_FINISH) + '): ' + IntToStr(Length(TIA)) + ' items [' + IntToStr(GetSystemTime - t) + ' ms.]' );
  SetLength(TIA, 0);
  t := GetSystemTime;
  TIA := TIAByRange2Bit(RANGE1_START, RANGE1_FINISH);
  WriteLn('TIAByRange2bit(' + IntToStr(RANGE1_START) + ', ' + IntToStr(RANGE1_FINISH) + '): ' + IntToStr(Length(TIA)) + ' items [' + IntToStr(GetSystemTime - t) + ' ms.]' );
  SetLength(TIA, 0);
  t := GetSystemTime;
  TIA := TIAByRange(RANGE2_START, RANGE2_FINISH);
  WriteLn('TIAByRange(' + IntToStr(RANGE2_START) + ', ' + IntToStr(RANGE2_FINISH) + '): ' + IntToStr(Length(TIA)) + ' items [' + IntToStr(GetSystemTime - t) + ' ms.]' );
  SetLength(TIA, 0);
  t := GetSystemTime;
  TIA := TIAByRange2Bit(RANGE2_START, RANGE2_FINISH);
  WriteLn('TIAByRange2bit(' + IntToStr(RANGE2_START) + ', ' + IntToStr(RANGE2_FINISH) + '): ' + IntToStr(Length(TIA)) + ' items [' + IntToStr(GetSystemTime - t) + ' ms.]' );
  SetLength(TIA, 0);
end.