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Код: Выделить всё

uses Crt;
type TreePointer = ^tree;
 tree = record
 data: string;
 left: TreePointer;
 right: TreePointer;
end;

var
root:TreePointer;
fail,rez:text;
nom:byte;
ns,name,put:string;

procedure Build(var p:TreePointer);
begin
 new(p);
 readln(fail,p^.data);
 if (p^.data ='+') or (p^.data='-') or (p^.data ='*') or (p^.data ='/') then
  begin
   Build(p^.left);
   Build(p^.right);
  end
  else
  if (p^.data='exp') or (p^.data ='ln') or (p^.data ='cos') or (p^.data ='sin') then
   begin
    p^.left:= nil;
    Build(p^.right);
   end
   else
    begin
     p^.left:= nil;
     p^.right:= nil;
    end
end;

procedure Infix(r:TreePointer);
 begin
  if r<>nil then
   begin
    Infix(r^.left);
    Write(r^.data);
    Infix(r^.right);
   end;
end;

procedure Prefix(r:TreePointer);
 begin
  if r<>nil then
   begin
    Write(r^.data);
    Prefix(r^.left);
    Prefix(r^.right);
   end;
 end;

procedure Postfix(r:TreePointer);
 begin
  if r<>nil then
   begin
    Postfix(r^.left);
    Postfix(r^.right);
    Write(r^.data);
   end;
 end;

begin
 clrscr;
 root := nil;
 write('Vvedite nomer faila s vhodnyni dannymi: ');
 readln(nom);
 str(nom,ns);
 name:='ex'+ns+'.in';
 clrscr;
 writeln('Fail: ',name);
 writeln('Vvedite put k failu,esli on nahoditsia ne v papke s programmoi: ');
 readln(put);
 if length(put)>0 then
  begin
   name:=put+name;
   clrscr;
   writeln('Fail: ',name);
   readln;
  end;
 assign(fail,name);
 reset(fail);
 if eof(fail)=true then
  begin
   writeln('Fail pust!');
   readln;
  end;
 while eof(fail)=false do Build(root);
 writeln('Priamoi obhod: ');
 Prefix(root);
 writeln;
 writeln('Obratnyi obhod: ');
 Postfix(root);
 writeln;
 writeln('Simmetrichnyi obhod: ');
 Infix(root);
 readln;
end.