Check whether the schedule overlaps each other?

问题

I need to find whether a new event created over laps any of the existing event.

Event Table

ID EventName StartTime EndTime 
1  Event1    11:30AM   12PM    
2  Event2    11:30AM   11:40AM 
3  Event3    11:40AM   12PM    
4  Event4    12PM      12:30PM 
5  Event5    11:30AM   12:30PM 

In above table, event 2 overlaps event 1, event 3 overlaps event 1, event 5 overlaps event 1...

Current event start time and existing schedule end time, current end time and existing schedule start time can be same.

I am trying to compare the whether the new event event time overlaps existing event time using the following logic but it fails

if (currentStartTime == schedule.StartTime)
{
count++;
continue;
}
else if (currentStartTime == schedule.EndTime)
{
continue;
}
else if (currentEndTime == schedule.StartTime)
{
continue;
}
else if (currentStartTime > schedule.StartTime && currentStartTime < schedule.EndTime     && currentEndTime >= schedule.EndTime)
{
count++;
continue;
}
else if (currentEndTime <= schedule.EndTime && currentEndTime > schedule.StartTime &&     currentStartTime < schedule.StartTime)
{
count++;
continue;
}

回答1:

It is probably simpler to invert the problem and ask "when do two intervals not overlap?" Answer: when the end of interval A is <= the start of interval B, or when the end of interval B is <= the start of interval A. Create an expression for this, and negate it.

回答2:

You may find the following article useful and especially the TimePeriodIntersector class.

来源：https://stackoverflow.com/questions/5565564/check-whether-the-schedule-overlaps-each-other