Meeting Rooms II (Min Rooms)

Question

## Problem

Given meeting intervals, return the minimum number of rooms required.

## Example
```
[[0,30],[5,10],[15,20]] -> 2
```

## Constraints
- 1 ≤ n ≤ 10^4

## Approach
Sort starts/ends, sweep; or min-heap of end times. Reported Splunk question.