SPA1 stack (kolokvijum)

MODULE stek;
(*Rad nad stekovima*)
(*Korisceni InfoTip je INTEGER, da bi se kao takav koristio, u Info.def promeniti
char(default) u integer*)
FROM InOut IMPORT WriteString, WriteLn, WriteInt, ReadInt;
FROM FIO IMPORT File, Open, Create, Close, WrInt, RdInt, WrLn, EOF;
FROM Stek IMPORT StekTip, Top, Pop, Push, MakeNull, Empty;
CONST
     fu = "ispis.txt";
     br = "brojevi.txt"
VAR
   f : File;
   k : INTEGER;
   s, q, w : StekTip;
   ok : BOOLEAN;

(*iz fajla upisuje elemente u stek*)
(*Proveriti!!! ponekad ne radi ova procedura*)
PROCEDURE unizf(VAR s: StekTip;VAR ok: BOOLEAN);
VAR
   f: File;
   n: INTEGER;
BEGIN
     MakeNull(s);
     EOF := FALSE;
     ok := TRUE;
     f := Open(br);
     WHILE (NOT EOF) AND (ok) DO
          n := RdInt(f);
          Push(s,n,ok)
     END;
     Close(f);
END unizf;

(*ispisuje elemente iz steka u zadati fajl*)
PROCEDURE iuf(s: StekTip);
VAR
   f: File;
   n: INTEGER;
   ok: BOOLEAN;
BEGIN
     f := Create(fu);
     ok := TRUE;
     WHILE (NOT Empty(s)) AND (ok) DO
          Top(s,n,ok);
          WrInt(f,n,0);
          WrLn(f);
          Pop(s,ok)
     END;
     Close(f);
END iuf;

(*stampanje steka*)
PROCEDURE ispissteka(s: StekTip);
VAR
   ok : BOOLEAN;
   n : INTEGER;
BEGIN
     IF NOT Empty(s) THEN
        ok := TRUE;
        WHILE (NOT Empty(s)) AND ok DO
              Top(s, n, ok);
              WriteInt(n,0);
              WriteLn;
              Pop(s,ok)
        END
     ELSE
         WriteString("Nema elemenata za stampanje =====");
         WriteLn;
     END;
END ispissteka;

(*uklanjamo elemente iz steka, Postoji procedura MakeNull(stel) *)
PROCEDURE ispraznistek(VAR s: StekTip);
VAR
   ok : BOOLEAN;
BEGIN
     WHILE NOT Empty(s) DO
          Pop(s,ok)
     END;
END ispraznistek;

(*od dva steka kreira se jedan novi*)
PROCEDURE proc1(q,w: StekTip;VAR s: StekTip;VAR ok: BOOLEAN);
VAR
   n : INTEGER;
   qem, wem : BOOLEAN;
BEGIN
     MakeNull(s);
     qem := Empty(q);
     wem := Empty(w);
     ok := TRUE;
     WHILE (NOT qem) OR (NOT wem) DO
          IF NOT qem THEN
           Top(q,n,ok);
           IF ok THEN
             Push(s,n,ok);
             Pop(q,ok)
           END
         END;
         IF NOT wem THEN
           Top(w,n,ok);
           IF ok THEN
             Push(s,n,ok);
             Pop(w,ok)
           END
         END;
         qem := Empty(q);
         wem := Empty(w)
     END
END proc1;

(*od jednog steka kreairaju se dva*)
PROCEDURE provera(s: StekTip): BOOLEAN;
VAR
   ok : BOOLEAN;
BEGIN
     IF NOT Empty(s) THEN
       Pop(s,ok);
       IF NOT Empty(s) THEN
         RETURN FALSE;
       END
     END;
     RETURN TRUE
END provera;

PROCEDURE proc2(s: StekTip;VAR q,w: StekTip);
VAR
   turn, ok : BOOLEAN;
   n: INTEGER;
BEGIN
     IF NOT provera(s) THEN
       MakeNull(q);
       MakeNull(w);
       turn := TRUE;
       ok := TRUE;
       WHILE (NOT Empty(s)) DO
            IF turn THEN
              Top(s,n,ok);
              IF ok THEN
                Push(q,n,ok);
                Pop(s,ok)
              END;
              turn := NOT turn
            END;

            IF NOT turn THEN
              Top(s,n,ok);
              IF ok THEN
                Push(w,n,ok);
                Pop(s,ok)
              END;
              turn := NOT turn
            END
       END
     ELSE
         IF (NOT Empty(s)) THEN
           MakeNull(q);
           Top(s,n,ok);
           Push(q,n,ok)
         ELSE
             WriteString("Pocetni stek je prazan! ")
         END
     END
END proc2;

(*Sa vrha steka ukloniti (neki uslov)*)
PROCEDURE jednocifren(n: INTEGER): BOOLEAN;
BEGIN
     IF (n DIV 10 = 0) THEN
       RETURN TRUE;
     ELSE
        RETURN FALSE;
     END
END jednocifren;

PROCEDURE proc3(VAR s: StekTip);
VAR
   pr, ok : BOOLEAN;
   n : INTEGER;
BEGIN
     IF NOT Empty(s) THEN
       pr := TRUE;
       WHILE  (NOT Empty(s)) AND (pr) DO
             Top(s,n,ok);
             (*ubaciti neki drugi uslov*)
             IF (jednocifren(n)) THEN
               Pop(s,ok)
             ELSE
                 pr := FALSE
             END
       END
     ELSE
         WriteString("Nema elemenata u prosledjenom steku!");
     END;
END proc3;

BEGIN
     MakeNull(s);
     Push(s,12,ok);
      Push(s,22,ok);
       Push(s,3,ok);
        Push(s,10,ok);

     MakeNull(q);
     Push(q,12,ok);
      Push(q,22,ok);
       Push(q,3,ok);
        Push(q,10,ok);


     MakeNull(w);
     Push(w,12,ok);
      Push(w,22,ok);
       Push(w,3,ok);
        Push(w,10,ok);

     ispissteka(s); WriteLn;
     ispissteka(q); WriteLn;
     ispissteka(w); WriteLn;

     (*ubaciti procedure za koriscenje*)

END stek.