with Text_io; use Text_io;
package body INTEGER_SETS is -- implemented by amorphous set(Botting 78)
-- LINK is access DATA, INTEGER_SETS renames LINK
-- NULL_SET = INTEGER_SET(NULL)
-- DANGER - equality betwwen LINKS and INTEGER_SETs is defined locally.
  package IIO is new Text_IO.Integer_io(integer); --need integer output
  use iio;
  n:constant INTEGER:=200;
  type ITEMS is array(1..N) of INTEGER;
  type DATA is record
	LASTI:INTEGER range 0..N:=0;
	ITEM: ITEMS:=ITEMS'(1..N=>0);
  end record;
 
  procedure Make_Empty(S:out INTEGER_SET) is -- after S=NULL_SET
  begin S:=NULL;
  end;
 
  function Member(I:integer; ISIN:INTEGER_SET) return boolean is
  begin if Empty(ISIN) then return false;
	end if;
	for P in 1..ISIN.LASTI loop 
		if ISIN.ITEM(P)=I then return true;
		end if;
	end loop;
	return false;
  end Member;
 
  function Empty(ISIN:INTEGER_SET) return boolean is
  begin return ISIN.LASTI=0;
  exception when CONSTRAINT_ERROR => return true; -- ISIN=NULL
  end Empty;
 
  function Full(ISIN:INTEGER_SET) return boolean is
  begin return not Empty(ISIN) and then ISIN.LASTI>=N;
  end Full;
 
  function Max(S:INTEGER_SET) return integer is
	M:INTEGER;
  begin
    if Empty(S) then raise EMPTY_GET;
    else
	M:=S.ITEM(S.ITEM'FIRST);
        for P in INTEGER'SUCC(S.ITEM'FIRST)..S.LASTI loop
           if M<S.ITEM(P)  then M:=S.ITEM(P);
           end if;
        end loop;
	return M;
    end if;
  end Max;
 
  function Min(S:INTEGER_SET) return integer is
	M:INTEGER;
  begin
    if Empty(S) then raise EMPTY_GET;
    else
	M:=S.ITEM(S.ITEM'FIRST);
        for P in INTEGER'SUCC(S.ITEM'FIRST)..S.LASTI loop
           if M>S.ITEM(P)  then M:=S.ITEM(P);
           end if;
        end loop;
	return M;
    end if;
  end MIN;
 
 
  procedure Put(S:in INTEGER_SET) is -- output set to standard output
  begin 
    Put('{');
    if not Empty(S)  then  -- one or more items (S.ITEN(1...))
      Put(S.ITEM(S.ITEM'FIRST));
      for I in INTEGER'SUCC(S.ITEM'FIRST)..S.LASTI loop 
	Put(", ");
	Put(S.ITEM(I));
      end loop;
    end if;
    Put('}');
  end Put;
 
  procedure Put(I:integer; INTO:in out INTEGER_SET) is -- put I into set S
  begin 
	declare DUMMY:DATA; 
	begin
		DUMMY:=INTO.all;
	exception when CONSTRAINT_ERROR => INTO:=new DATA;
	end;
 
	if INTO.LASTI=N then raise FULL_PUT;
	end if;
 
	INTO.LASTI:=INTO.LASTI+1;
	INTO.ITEM(INTO.LASTI):=I;
  end Put;
 
  procedure Take(I: integer; FROM:in out INTEGER_SET) is--take I out
  begin if Empty(FROM) then return;
	end if;
	for P in FROM.ITEM'FIRST..FROM.LASTI loop
		if FROM.ITEM(P)=I then
			FROM.ITEM(P):=FROM.ITEM(FROM.LASTI);
			FROM.LASTI:=FROM.LASTI-1;
			return;
		end if;
	end loop;
  end Take;
 
  procedure Getmin(I: out integer; FROM:in out INTEGER_SET) is
	M:integer:=MIN(FROM);
  begin
	I:=M; TAKE(M,FROM);
  end Getmin;
 
  procedure GetMax(I: out integer; FROM: in out INTEGER_SET) is
        M:integer:=MAX(FROM);
  begin
        I:=M; TAKE(M,FROM);
  end GetMax;
 
  procedure Get(I: out integer; FROM:in out INTEGER_SET) is
  begin
    if Empty(FROM) then
      raise EMPTY_GET;
    else
	I:=FROM.ITEM(FROM.LASTI); FROM.LASTI:=FROM.LASTI-1;
    end if;
    if FROM.LASTI=0 then FROM:=NULL;
    end if;
  end Get;
 
  function  "="(LEFT,RIGHT:INTEGER_SET) return boolean is
  begin
	if Empty(LEFT) or Empty(RIGHT) then
		return Empty(LEFT) and EMPTY(RIGHT);
	end if;
	if LEFT.LASTI /= RIGHT.LASTI then return FALSE;
	end if;
	-- here, LEFT and RIGHT have the same number of elements
	-- they may be in different orders.
	for i in LEFT.ITEM'FIRST..LEFT.LASTI loop
		if not member(LEFT.ITEM(I), RIGHT) or
		   not member(RIGHT.ITEM(I), LEFT) then return false;
		end if;
	end loop;
  end "=";
end INTEGER_SETS;