LeetCode 252 Meeting Rooms - Example and Complexity Analysis

Trace intervals = [[7,10],[2,4],[5,6]].

Sort by start: [[2,4],[5,6],[7,10]].

Check pairs:

• [2,4] and [5,6]: 5 >= 4. No overlap.
• [5,6] and [7,10]: 7 >= 6. No overlap.

All meetings can be attended. Return true.

Trace [[0,30],[5,10],[15,20]]. After sorting: [[0,30],[5,10],[15,20]].

• [0,30] and [5,10]: 5 < 30. Overlap! Return false.

$O(n \log n)$ time for sorting. $O(1)$ extra space (or $O(n)$ depending on sort).