/** GeomReihe
  * calculates geomReihe elements
*/

public class GeomReihe {

    public static double geomReiheIterativ(double first, double q, int n) {
        double ergebnis = first;
        for (int i = 1; i < n; i++) {
            ergebnis *= q;
        }
        return ergebnis;
    }

    public static double geomReiheRekursiv(double first, double q, int n) {
        if (n == 1)
            return first;
        return q * geomReiheRekursiv(first, q, n - 1);
    }
    
    
    public static void main(String[] args) {
        double[] testQs = { 0.1, 0.9, 1.0, 1.5};
        double first = 2.0;
        final int numberOfNs = 10;
        
        for (int j = 0; j < testQs.length; j++) {
            System.out.printf(">>>>>> neues q=%g\n",testQs[j]);
                for (int n = 1; n <= numberOfNs; n++) {
                    System.out.printf("Iterativ: n=%d first=%g q=%g ergebnis=%g\n",
                        n, first, testQs[j], geomReiheIterativ(first, testQs[j], n));
                    System.out.printf("Rekursiv: n=%d first=%g q=%g ergebnis=%g\n",
                        n, first, testQs[j], geomReiheRekursiv(first, testQs[j], n));
                }
            } 
    } // EO main

}