Algorithm Math Delphi

Title: Sort a TStringGrid by Columns?
type
TMoveSG = class(TCustomGrid); // reveals protected MoveRow procedure
{...}
procedure SortGridByCols(Grid: TStringGrid; ColOrder: array of Integer);
var
i, j: Integer;
Sorted: Boolean;
function Sort(Row1, Row2: Integer): Integer;
var
C: Integer;
begin
C := 0;
Result := AnsiCompareStr(Grid.Cols[ColOrder[C]][Row1], Grid.Cols[ColOrder[C]][Row2]);
if Result = 0 then
begin
Inc(C);
while (C and (Result = 0) do
begin
Result := AnsiCompareStr(Grid.Cols[ColOrder[C]][Row1],
Grid.Cols[ColOrder[C]][Row2]);
Inc(C);
end;
end;
end;
begin
if SizeOf(ColOrder) div SizeOf(i) Grid.ColCount then Exit;
for i := 0 to High(ColOrder) do
if (ColOrder[i] or (ColOrder[i] = Grid.ColCount) then Exit;
j := 0;
Sorted := False;
repeat
Inc(j);
with Grid do
for i := 0 to RowCount - 2 do
if Sort(i, i + 1) 0 then
begin
TMoveSG(Grid).MoveRow(i + 1, i);
Sorted := False;
end;
until Sorted or (j = 1000);
Grid.Repaint;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
{ Sort rows based on the contents of two or more columns.
Sorts first by column 1. If there are duplicate values
in column 1, the next sort column is column 2 and so on...}
SortGridByCols(StringGrid1, [1, 2, 0, 3, 4]);
end;