## Simultaneously Aggregating Overlapping Ranges (A Rectangle Problem)

问题 My Problem Consider a set of data with two intervals. For instance, consider a student schedule of classes. Each record has a begin and end date, and each class has a period start time and a period end time. But this schedule is not 'normalized' in the sense that some records overlap. So if you search for records encompassing a given date and period for a student, you might get multiple matches. Here's a contrived example. I represent the dates as integers to simplify the problem: declare