import java.util.ArrayList;

class FlexHistogram implements Histogram {
    private ArrayList<Double> _values = new ArrayList<>();
    int _size;
    double _low, _high;
    private int[] _count;

    public FlexHistogram(int size) {
        _size = size;
        _count = null;
    }

    public int size() {
        return _size;
    }
    
    public double low(int k) {
        makeCount();
        return _low + k * (_high - _low)/_size;
    }

    public void add(double x) {
        _count = null;
        _values.add(x);
    }

    public int count(int k) {
        makeCount();
        return _count[k];
    }

    private void makeCount() {
        if (_count == null) { 
            _count = new int[_size];
            if (_values.size() == 0) {
                _low = _high = 0.0;
                return;
            }
            _low = Double.MAX_VALUE;
            _high = Double.MIN_VALUE;
            for (double val : _values) {
                _low = Math.min(_low, val);
                _high = Math.max(_high, val);
            }
            for (double val : _values) {
                if (val >= _high) {
                    _count[_count.length - 1] += 1;
                } else {
                    int bucket = (int) ((val - _low)/(_high - _low)
                                        * _count.length);
                    _count[bucket] += 1;
                }
            }
        }
    }
}