Binomni koeficijent1

MODULE Binomni_koef1;
FROM InOut IMPORT WriteString, WriteLn, WriteInt, ReadInt, WriteCard;

CONST
     granica = 20;
VAR
   n, k, rezultat : INTEGER;
   ok : BOOLEAN;


PROCEDURE F(stari, n, k: INTEGER; VAR ok: BOOLEAN): INTEGER;
BEGIN
     ok := MAX(INTEGER) DIV (n-k+1) >= stari;
     IF ok THEN
       RETURN stari * (n-k+1) DIV k
     ELSE
       RETURN stari
     END;
END F;

PROCEDURE BINk(n,k: INTEGER; VAR ok: BOOLEAN): INTEGER;
VAR
   i, rezultat : INTEGER;
BEGIN
     ok := TRUE;
     IF (0 < n) AND (n <= granica) AND (k >= 0) THEN
       IF k > n THEN
         RETURN 0
       ELSE
         IF k > n -k THEN
           k := n - k
         END;
         rezultat := 1;
         i := 1;
         WHILE (i <= k) AND ok DO
           rezultat := F(rezultat, n, i, ok);
           i := i +1
         END;
         RETURN rezultat
       END
     ELSE
         ok := FALSE
     END;
     RETURN 0
END BINk;



BEGIN
     WriteString('Unesite prirodan broj n, 0 <= n <=');
     WriteCard(granica,0);
     WriteLn;
     ReadInt(n);
     WriteLn;
     WriteString('Unesite prirodan broj k >= 0');
     ReadInt(k);
     WriteLn;
     rezultat := BINk(n,k,ok);
     IF ok THEN
       WriteLn;
       WriteString('Rezultat: ');
       WriteInt(rezultat,0)
     ELSE
       WriteString('Greska! ')
     END;

END Binomni_koef1.