Паскаль (I семестр) / K02-172 / 05 / queue_st

{$R+}
program queue_static;
(*
(c) 2005 Dima Zolotukhin aka 'Zlogic' <zlogic@gmail.com>
Redistributable under GNU GPL license
*)

const
MAX_FIFO = 5;

type
str_message = string[70];
arr = record
data:array[1..MAX_FIFO]of integer;
head,tail:byte;
end;

procedure print_menu;
begin
writeln;
writeln('<< Њ…Ќћ ‘’Ђ’€—…‘ЉЋ‰ Ћ—…ђ…„€ >>');
writeln('1 „®Ў ўЁвм н«Ґ¬Ґ­в');
writeln('2 ‚лв йЁвм н«Ґ¬Ґ­в');
writeln('3 ‚л室');
end;

function get_int(message:str_message):integer;
var
response:integer;
begin
write(message,'> ');
readln(response);
get_int:=response;
end;

function shift(start:byte;step:shortint):byte;
var
new_pos:integer;
begin
new_pos:=step+start;
if(new_pos>MAX_FIFO)then
new_pos:=new_pos-MAX_FIFO;
if(new_pos<1)then
new_pos:=MAX_FIFO-new_pos;
shift:=new_pos;
end;

function queue_add(var _queue:arr;data_to_add:integer):boolean;
begin
if(shift(_queue.head,-1)<>_queue.tail)then{Ґб«Ё ¤«Ё­  ®зҐаҐ¤Ё ­Ґ ¬ ЄбЁ¬ «м­ }
begin
if(_queue.head=0)then{Ґб«Ё ®зҐаҐ¤м Їгбв п}
begin
_queue.head:=1;{Ё­ЁжЁ «Ё§Ёа㥬 Ј®«®ўг Ё еў®бв}
_queue.tail:=1;
end
else{Ё­ зҐ}
_queue.tail:=shift(_queue.tail,1);{¤ўЁЈ Ґ¬ еў®бв}
_queue.data[_queue.tail]:=data_to_add;{¤®Ў ў«пҐ¬ н«Ґ¬Ґ­в ў Є®­Ґж}
queue_add:=true;
end
else{Ё­ зҐ}
queue_add:=false;{®иЁЎЄ }
end;

function queue_get(var _queue:arr;var data_out:integer):boolean;
begin
if(_queue.head<>0)then{Ґб«Ё ®зҐаҐ¤м ­ҐЇгбв п}
begin
data_out:=_queue.data[_queue.head];{Ї®«гз Ґ¬ §­ зҐ­ЁҐ}
_queue.head:=shift(_queue.head,1);{¤ўЁЈ Ґ¬ Ј®«®ўг}
if(shift(_queue.head,-1)=_queue.tail)then{Ґб«Ё ®зҐаҐ¤м Їгбв п}
begin
_queue.head:=0;{®Ў­г«пҐ¬ Ї®Ё­вҐал}
_queue.tail:=0;
end;
queue_get:=true;
end
else{Ё­ зҐ}
queue_get:=false;{®иЁЎЄ }
end;

var
exit:boolean;
response:byte;
_queue:arr;
x:integer;
begin
exit:=false;
_queue.head:=0;
_queue.tail:=0;
while not exit do{Ї®Є  ­Ґ ­г¦­® ўл©вЁ}
begin
print_menu;{Ї®Є §лў Ґ¬ ¬Ґ­о}
response:=get_int('‚лЎҐаЁвҐ ў аЁ ­в');{зЁв Ґ¬ ®вўҐв Ї®«м§®ў вҐ«п}
writeln;
case response of
1:if not queue_add(_queue,get_int('‚ўҐ¤ЁвҐ, зв® ¤®Ў ўЁвм ў ®зҐаҐ¤м'))then{¤®Ў ў«Ґ­ЁҐ н«Ґ¬Ґ­в  ў ®зҐаҐ¤м}
writeln('<< Ћ—…ђ…„њ Џ…ђ…ЏЋ‹Ќ…ЌЂ >>');
2:begin
if queue_get(_queue,x) then{Ґб«Ё ®зҐаҐ¤м ­ҐЇгбв п}
writeln('Џ®«г祭® Ё§ ®зҐаҐ¤Ё: ',x){ўлў®¤Ё¬ н«Ґ¬Ґ­в}
else{Ё­ зҐ}
writeln('<< Ћ—…ђ…„њ Џ“‘’Ђџ >>');{ўлў®¤Ё¬ error}
end;
3:exit:=true;{ўл室}
end;
end;
end.