How should I practice Earliest Meeting Start on a 24-Hour Clock?

Start by reading the full statement, solve the visible examples, then compare the pattern against related IMC Trading online assessment problems in FastPrep.

Is Earliest Meeting Start on a 24-Hour Clock associated with IMC Trading?

FastPrep tags this as a IMC Trading online assessment coding practice problem when the problem catalog has that company and stage context.

Earliest Meeting Start on a 24-Hour Clock

IMC Trading● MediumFULLTIMEOA

Problem statement

Source note: The report says: "A variant of Insert Intervals. Given a set of meetings where time goes from 00:00 to 23:59, check if a new meeting with given start time and duration can be scheduled, if yes when is the earliest it can be scheduled in the day? Note that work goes on 24 hours so a 4 hour meeting can be from 10pm to 2am the next day as well. If a meeting ends at 9am, the next meeting needs to start at 9:01am (not 9am)."

The report does not give the input format, whether the meetings repeat the next day, how the given start time limits the search, or what to return when nothing fits. Here, times are "HH:MM" strings, a meeting that ends earlier in the day than it starts runs past midnight, and the meetings repeat every day. You look for the earliest start from the given start time to 23:59, and you return "-1" when nothing fits. Meetings may overlap and come in any order.

The judged task matches the report at about 80%.

Work runs all day and night, so a meeting can start late in the evening and end after midnight. Times use a 24-hour clock in "HH:MM" form, from "00:00" to "23:59", and every time is a whole minute.

You are given the meetings that already happen every day. Each meetings[i] = [from, to] uses every minute from from to to, including both of them. If to is earlier in the day than from, the meeting runs past midnight and ends at to the next day.

You want to add one new meeting that lasts duration minutes. If it starts at time t, it ends at duration minutes after t and uses every minute from t to its end, including both. It may run past midnight into the next day.

The new meeting must not share any minute with another meeting. So if a meeting ends at 09:00, the next meeting can start at 09:01 at the earliest. Because the meetings happen every day, the part of the new meeting after midnight must also avoid the meetings at those times.

Return the earliest start time, at or after start and no later than "23:59", at which the new meeting fits. Return it in "HH:MM" form. If no such start time exists, return "-1".

The meetings can be given in any order and can overlap each other.

Function

earliestMeetingStart(meetings: String[][], start: String, duration: int) → String

Examples

Example 1

meetings = [["09:00","10:00"],["10:30","11:00"]]start = "09:30"duration = 15return = "10:01"

From 09:30 to 10:00 the first meeting is running. It still uses 10:00, so the earliest free start is 10:01.

A 15-minute meeting from 10:01 ends at 10:16, which is before the meeting at 10:30. So the answer is "10:01".

Example 2

meetings = [["02:30","03:00"],["20:00","22:00"]]start = "21:00"duration = 240return = "22:01"

The meeting from 20:00 to 22:00 blocks every start up to 22:00.

A 4-hour meeting from 22:01 runs past midnight and ends at 02:01 the next day. That is before the 02:30 meeting, so it fits and the answer is "22:01".

Example 3

meetings = [["01:00","02:00"],["21:00","22:00"]]start = "20:00"duration = 240return = "-1"

A start from 20:00 to 22:00 runs into the meeting from 21:00 to 22:00.
A start from 22:01 to 23:59 ends at 02:01 or later the next day. The meetings repeat every day, so it runs into the meeting from 01:00 to 02:00.

No start from 20:00 to 23:59 works, so the answer is "-1", even though a start such as 16:00 would fit.

Example 4

meetings = [["22:00","01:00"]]start = "00:30"duration = 30return = "01:01"

The meeting from 22:00 to 01:00 runs past midnight, so it also uses every minute from 00:00 to 01:00.

The first free start at or after 00:30 is 01:01, and a 30-minute meeting from there ends at 01:31.

Constraints

0 <= meetings.length <= 1000
meetings[i].length == 2
Every time in meetings and start is a string in "HH:MM" form from "00:00" to "23:59".
meetings[i][0] != meetings[i][1]
1 <= duration <= 1439