Here’s a version using yield return
– I find it easier to read than doing an Aggregate
query, although it’s still lazy evaluated. This assumes you’ve ordered the list already, if not, just add that step.
IEnumerable<Interval> MergeOverlappingIntervals(IEnumerable<Interval> intervals)
{
var accumulator = intervals.First();
intervals = intervals.Skip(1);
foreach(var interval in intervals)
{
if ( interval.Start <= accumulator.End )
{
accumulator = Combine(accumulator, interval);
}
else
{
yield return accumulator;
accumulator = interval;
}
}
yield return accumulator;
}
Interval Combine(Interval start, Interval end)
{
return new Interval
{
Start = start.Start,
End = Max(start.End, end.End),
};
}
private static DateTime Max(DateTime left, DateTime right)
{
return (left > right) ? left : right;
}