SPA1 Polinom H/Advanced #izracunaj

MODULE Polinomic;
FROM InOut IMPORT WriteString, WriteLn;
FROM RealInOut IMPORT WriteReal;
FROM Storage IMPORT ALLOCATE, DEALLOCATE;
FROM PolinomL IMPORT Polinom, UbaciMonom, Stampaj, Anuliraj;

(*izracunaj //polinom, naprednija*)
PROCEDURE izracunaj(a: REAL;p: Polinom;VAR pro: BOOLEAN): REAL;

  (*Izracunavanje stepena uzastopnim kvadriranjem*)
  PROCEDURE Stepen(a: REAL; n: INTEGER; VAR ok: BOOLEAN): REAL;

        PROCEDURE Sqr(x: REAL): REAL;
        BEGIN
             RETURN x*x
        END Sqr;

        PROCEDURE RekStepen(a: REAL; n: INTEGER): REAL;
        BEGIN
             IF n = 1 THEN
               RETURN a
             ELSIF ODD(n) THEN
                  RETURN a * Sqr(RekStepen(a,n DIV 2))
             ELSE
                 RETURN Sqr(RekStepen(a,n DIV 2))
             END;
        END RekStepen;

  BEGIN
     IF (a = 0.0) AND (n <= 0) THEN
       ok := FALSE;
       RETURN 0.0
     ELSE
         ok := TRUE;
         IF a = 0.0 THEN
           RETURN 0.0
         ELSIF (n = 0) OR (a = 1.0) THEN
              RETURN 1.0
         ELSIF n = 1 THEN
              RETURN a
         ELSE
             IF n < 0 THEN
               a := 1.0 / a;
               n := ABS(n)
             END;
             RETURN RekStepen(a, n)
         END
     END
  END Stepen;

VAR
   tekuci: Polinom;
   akum: REAL;
   rez: REAL;
BEGIN
        rez := 0.0;
    tekuci := p;
        pro := TRUE;
    WHILE (tekuci <> NIL) AND pro DO
             akum := Stepen(a, tekuci^.st, pro);
             rez := rez + tekuci^.k * akum;
             tekuci := tekuci^.veza;
    END;
        RETURN rez;

END izracunaj;

VAR
   monom, polinom: Polinom;
   rez : REAL;
   ok : BOOLEAN;


BEGIN
     Anuliraj(polinom);

     NEW(monom);
     monom^.st := 3;
     monom^.k := 2.0;
     monom^.veza := NIL;
     UbaciMonom(monom, polinom);
     DISPOSE(monom);

     NEW(monom);
     monom^.st := 2;
     monom^.k := 5.0;
     monom^.veza := NIL;
     UbaciMonom(monom, polinom);
     DISPOSE(monom);

     NEW(monom);
     monom^.st := 1;
     monom^.k := 3.0;
     monom^.veza := NIL;
     UbaciMonom(monom, polinom);
     DISPOSE(monom);

     NEW(monom);
     monom^.st := 0;
     monom^.k := 5.0;
     monom^.veza := NIL;
     UbaciMonom(monom, polinom);
     DISPOSE(monom);

     WriteString('Polinom pre procedure:  ');
     Stampaj(polinom,0);
     WriteLn; WriteLn;

     rez := izracunaj(2.0,polinom,ok);
     WriteString('Rez je:  ');
     WriteReal(rez,0);



END Polinomic.