procedure TForm1.MakeTree(PF:string;NN:integer);
var Tree:PTree;

var i:byte;

function MakeBranch(var PF:string):PTree;
var t:PTree;
begin
     if PF[length(PF)]='x'
     then begin
          new(t);
          t^.Oper:=#0;
          t^.Number:=StrToFloat(StringGrid1.Cells[0,NN-1]) ;
          dec(NN);
          delete(PF,length(PF),1);
          t^.Right:=nil;
          t^.Left:=nil;
     end
     else begin
          new(t);
          t^.Oper:=PF[length(PF)];
          t^.Number:=0;
          delete(PF,length(PF),1);
          t^.Right:=MakeBranch(PF);
          t^.Left:=MakeBranch(PF);
     end;
     MakeBranch:=t;
end;

function EvalTree(t:PTree):real;
begin
     if t^.Oper=#0
     then EvalTree:=t^.Number
     else case t^.Oper of
               '+':EvalTree:=EvalTree(t^.Left)+EvalTree(t^.Right);
               '-':EvalTree:=EvalTree(t^.Left)-EvalTree(t^.Right);
               '*':EvalTree:=EvalTree(t^.Left)*+EvalTree(t^.Right);
               '/':EvalTree:=EvalTree(t^.Left)/EvalTree(t^.Right);
          end;

end;

procedure DelTree(t:PTree);
begin
     if t<>nil
     then begin
          DelTree(t^.Left);
          DelTree(t^.Right);
          dispose(t);
     end;
end;

begin
     i:=0;
     Tree:=MakeBranch(PF);
     Label5.Caption:=FloatToStr(EvalTree(Tree));
     DelTree(Tree);
end;