program8.pl0

编译原理课程设计大作业PL0文法简易编译器

var x,y,m,n:integer;
var pf:boolean;
procedure prime;
var i:boolean;
var f:integer;
  procedure mod;
    x:=x-x/y*y;
begin
  f:=true;
  i:=3;
  while i<m do
    begin
      x:=m;
      y:=i;
      call mod;
      if x=0 then f:=false;
      i:=i+2
    end;
  if f=true then
    begin
      write(m);
      pf:=true
    end
end;
begin
  pf:=false;
  read(n);
  while n>=2 do
  begin
    write(2);
    if n=2 then pf:=true;
    m:=3;
    while m<=n do
      begin
        call prime;
        m:=m+2
      end;
    read(n)
  end;
  if pf=false then write(0)
end.