Beanmachine

import java.util.*;

public class BeanMachine {

    private static final int PEAK_HEIGHT = 50;
    private static final char BAR_CHAR = '*';

    private Random rgen;
    private int size, balls;
    private int[] buckets;
    private String format;

    public BeanMachine(int size) {
        rgen = new Random();
        this.size = size;
        buckets = new int[size];
        int numLen = (int) Math.ceil(Math.log10(size));
        format = "Bucket%0" + numLen +"d: ";
        reset();
    }

    public void reset() {
        for (int i = 0; i < size; i++) {
            buckets[i] = 0;
        }
        balls = 0;
    }

    public void dropBall() {
        int pos = 0;
        for (int i = 1; i < size; i++) {
            pos += rgen.nextInt(2) == 0 ? 0 : 1;
        }
        buckets[pos]++;
        balls++;
    }

    public int getNumBalls() {
        return balls;
    }

    public void showBucketCounts() {
        for (int i = 0; i < size; i++) {
            System.out.printf(format + "%d\n", i, buckets[i]);
        }
    }

    public void showBucketGraph() {
        int highest = buckets[0];
        for (int i = 1; i < size; i++) {
            int curr = buckets[i];
            if (curr > highest) {highest = curr;}
        }
        double heightFactor = (double) PEAK_HEIGHT / highest;
        for (int i = 0; i < size; i++) {
            System.out.printf(format, i);
            int barLen = (int) Math.round(buckets[i] * heightFactor);
            String bar = "";
            for (int j = 0; j < barLen; j++) {
                bar += BAR_CHAR;
            }
            System.out.println(bar);
        }
    }

    public static void main(String[] args) {
        BeanMachine bt = new BeanMachine(101);
        for (int i = 0; i < 1_000_000; i++) {
            bt.dropBall();
        }
        bt.showBucketGraph();
        System.out.println();
        bt.showBucketCounts();
    }
}