Montecarlo

public class Montecarlo {

    private static int FALLIDO = 0;
    private static int SIN_FALLA = 1;
    private static int MAX_TIRADAS = 9999999;
    private static double EPSILON = 0.000001;
    private int fallidos = 5;
    private int sin_fallas = 5;
    private int totales = 10;

    public Montecarlo() {}

    public double getProbability(){
         int exitos = 0;
         int tiradas = 0;
         double prob_ant = -1;
         double prob_act = 0;
         while(!converge(prob_ant,prob_act,tiradas)) {
             int p1 = getProduct();
             int p2 = getProduct();
             int p3 = getProduct();
            if ( (p1 == FALLIDO) && (p2 == FALLIDO ) && (p3 == FALLIDO) )
                 exitos ++;
            tiradas ++;
            prob_ant = prob_act;
            prob_act = (double) exitos/tiradas;
            resetValues();
         }

        return prob_act;
    }

    private void resetValues() {
        fallidos = 5;
        sin_fallas = 5;
        totales = 10;
    }

    private int getProduct(){
        double fallas =(double) fallidos / totales;
        double[] prob_acum = {fallas,1.0F};
        double r = Math.random();

        for(int i = 0; i < prob_acum.length;i++) {

            if (r < prob_acum[i] && i == FALLIDO ) {
                totales --;
                fallidos--;
                return i;
            }
            else if(r < prob_acum[i] && i == SIN_FALLA ) {
                totales --;
                sin_fallas--;
                return i;
            }
        }
        return -1;
    }

    boolean converge( double ant, double  act, int tiradas) {
        if((Math.abs(ant- act) < EPSILON) && tiradas > MAX_TIRADAS)
            return true;
        return false;
    }
}