/// <summary>
/// return the number of intervals containing 'x' in
/// Complexity: o(log(n)) (+ o(n log(n) ) preparation time)
/// (where 'n' is the total number of interval)
/// </summary>
/// <param name="x"></param>
/// <returns>number of intervals containing x</returns>
public int CountIntervalsContaining(int x)
{
if (x < _center || (x == _center && !_endOfIntervalIsIncludedInInterval))
{
return((_left?.CountIntervalsContaining(x) ?? 0)
+ MaximumValidIndex(0, _intervalsSortedByStart.Count, idx => (idx == 0) || _intervalsSortedByStart[idx - 1].Item1 <= x));
}
else
{
return((_right?.CountIntervalsContaining(x) ?? 0)
+ MaximumValidIndex(0, _intervalsSortedByEnd.Count, idx => (idx == 0) ||
_intervalsSortedByEnd[_intervalsSortedByEnd.Count - idx].Item2 > x ||
(_endOfIntervalIsIncludedInInterval && _intervalsSortedByEnd[_intervalsSortedByEnd.Count - idx].Item2 == x)
));
}
}
