Gerard

package BinaryTree;
import java.util.ArrayDeque;

public final class BalancedNumbers {
    private ArrayDeque<Integer> nums = new ArrayDeque<Integer>();
    private ArrayDeque<Range>   todo = new ArrayDeque<Range>();

    public BalancedNumbers(int a, int b) {
        todo.addLast(new Range(a, b));

        while(!todo.isEmpty()) {
            calculate();
        }
    }

    public Integer[] getNums() {
        Integer[] arr = new Integer[nums.size()];

        return nums.toArray(arr);
    }

    public void calculate() {
        Range range = todo.removeFirst();
        if(range.a == range.b) return;

        double middle = range.a + ((range.b - range.a) * .5);

        if(Math.floor(middle) == 0) {
            todo.clear();
            return;
        }
        nums.addLast(((int)Math.floor(middle)));
        Range range1 = new Range(range.a, (int)Math.floor(middle));
        Range range2 = new Range((int)Math.ceil(middle), range.b);
        todo.addLast(range1);
        todo.addLast(range2);
    }
}

class Range {
    public int a;
    public int b;
    public Range(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public String toString() {
        return "a: " + a + ", b:" + b + " ";
    }
}