Merge overlapping trading sessions

Question

A venue publishes trading sessions as [open, close] time intervals, but some overlap or touch. Merge them into the fewest disjoint intervals that cover the same time. Return the merged, non-overlapping sessions sorted by start. Aim for O(n \log n).

Accepted Answer

Sort by start time. Walk the sorted list keeping the last merged interval on top of a result list. If the next session starts at or before the current end, they overlap (or touch), so extend the end to the larger of the two closes; otherwise the next session is disjoint and starts a new entry. Tracing the example: [9, 11] lands first; [10, 12] starts at 10 <= 11, so it fuses into [9, 12]; [13, 14] starts after 12, so it stands alone. Time O(n \log n) for the sort, space O(n) for the output. Two edge cases matter: use <= if touching intervals like [1, 2] and [2, 3] should merge, and always tak…

Merge overlapping trading sessions

Your answer

More Coding questions