Multiple Date range comparison for overlap: how to do it efficiently?

Question

To check for overlap in two different dateranges, {Start1, End1} and {Start2, End2} I am checking:

if ((Start1 <= End2) && (End1 >= Start2))
{
  //overlap exists
}

The question is, what is a good way to compare overlaps if I had let's say five dateranges?.

checking to see if any of them don't overlap each other?

If I have multiple date ranges, how to find if any of these ranges are overlapping?

Answer 1

To find if all are overlapping

static bool Overlap(params Tuple<DateTime, DateTime>[] ranges)
{
    for (int i = 0; i < ranges.Length; i++)
    {
        for (int j = i + 1; j < ranges.Length; j++)
        {
            if (!(ranges[i].Item1 <= ranges[j].Item2 && ranges[i].Item2 >= ranges[j].Item1))
                return false;

        }
    }
    return true;
}

to find if any are overlapping

static bool Overlap(params Tuple<DateTime, DateTime>[] ranges)
{
    for (int i = 0; i < ranges.Length; i++)
    {
        for (int j = i + 1; j < ranges.Length; j++)
        {
            if (ranges[i].Item1 <= ranges[j].Item2 && ranges[i].Item2 >= ranges[j].Item1)
                return true;

        }
    }
    return false;
}