Решение СЛАУ методом Гусса

unit Unit4;
 
interface
 
uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Samples.Spin,
  Vcl.Grids;
 
type
  TForm4 = class(TForm)
    StringGrid1: TStringGrid;
    StringGrid2: TStringGrid;
    StringGrid3: TStringGrid;
    SpinEdit1: TSpinEdit;
    Button1: TButton;
    procedure SpinEdit1Change(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form4: TForm4;
  i,j,k,n,z:integer;
  h:double;
  b,x:array[1..100] of real;
  a: array[0..50,0..50] of real;
 
 
implementation
 
{$R *.dfm}
procedure TForm4.SpinEdit1Change(Sender: TObject);
begin
z:=strtoint(SpinEdit1.Text);
n:=z;
StringGrid1.rowcount:=n;
StringGrid2.rowcount:=n;
 StringGrid3.rowcount:=n;
StringGrid1.colcount:=n;
end;
 
procedure TForm4.Button1Click(Sender: TObject);
begin
 for j:=0 to n-1 do
for i:=0 to n-1 do begin
a[i+1,j+1]:=StrToFloatDef(StringGrid1.Cells[j,i],0);
  if StringGrid1.Cells[i,j]='' then exit;
end;
 
for I := 0 to n-1 do
b[i+1] := StrToFloatDef(StringGrid2.Cells[0,i],0);
 
for i:=1 to n-1 do
for j:=i+1 to n do
begin
a[j,i]:=-a[j,i]/a[i,i];
for k:=i+1 to n do
a[j,k]:=a[j,k]+a[j,i]*a[i,k];
b[j]:=b[j]+a[j,i]*b[i];
end;
x[n]:=b[n]/a[n,n];
for i:=n-1 downto 1 do
 
begin
h:=b[i];
for j:=i+1 to n do h:=h-x[j]*a[i,j];
x[i]:=h/a[i,i]
end;
for i:=1 to n do
Stringgrid3.cells[i,1]:=floattostr(x[i]);
end;
end.