How should I practice Generate Available Time Slots?

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Problem · Simulation

Generate Available Time Slots

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You are given a datetime range [startDate, endDate] and a weekly recurring working-hours configuration.

Generate every available 30-minute slot that is fully contained in the range and also lies inside one of the working-hour windows for the corresponding weekday.

Each slot is represented as a string "start,end", where the start and end timestamps are separated by a comma.

The first and last days must be validated using the exact time boundaries: a slot is valid only when slotStart >= startDate and slotEnd <= endDate.

Function Description

Complete the function generateAvailableTimeSlots in the editor below.

generateAvailableTimeSlots has the following parameters:

String startDate: inclusive lower datetime bound in YYYY-MM-DD HH:MM format
String endDate: inclusive upper datetime bound in YYYY-MM-DD HH:MM format
String[][] workingHours: each row is [weekday, windowStart, windowEnd], where weekday is 0 for Monday through 6 for Sunday

Returns

String[]: all valid 30-minute slots in chronological order.

Examples

01 · Example 1

startDate = "2026-01-05 09:10"
endDate = "2026-01-05 10:40"
workingHours = [["0", "09:00", "12:00"]]
return = ["2026-01-05 09:30,2026-01-05 10:00", "2026-01-05 10:00,2026-01-05 10:30"]

The 09:00-09:30 slot starts before the allowed range, and the 10:30-11:00 slot ends after the allowed range. The two middle 30-minute slots are fully contained.

02 · Example 2

startDate = "2026-01-06 13:00"
endDate = "2026-01-06 14:00"
workingHours = [["1", "12:30", "14:30"]]
return = ["2026-01-06 13:00,2026-01-06 13:30", "2026-01-06 13:30,2026-01-06 14:00"]

Only the two full 30-minute slots inside both the Tuesday working window and the requested datetime range are returned.

Constraints

workingHours repeats weekly.
Only full 30-minute slots are emitted.
Output must be sorted chronologically.