Reusable Cyclic Barrier
Apple● MediumFULLTIMEPHONE SCREENProblem statement
Implement the waiting and reusable-generation behavior of a cyclic barrier through an ordered finite arrival trace. For this exercise, the barrier has a positive number of parties and starts in generation0.
Each entry in participantIds submits one atomic arrival-and-wait call. Once exactly parties calls have arrived in the current generation, release all of them together and advance to the next generation. Before release, a participant cannot submit another call. After release, that participant may immediately arrive in a later generation. Inputs satisfy this rule; a generation need not use the same participants as the previous one.
Return the final result for each arrival after the entire trace: RELEASE g if generation g completed, or WAIT g if its last group is still incomplete. Generation numbers are decimal integers starting at0. No broken-barrier, reset, cancellation or timeout behavior is included.
Function
runCyclicBarrier(parties: int, participantIds: int[]) → String[]Examples
Example 1
parties = 2participantIds = [1,2,1]return = ["RELEASE 0","RELEASE 0","WAIT 1"]The first two arrivals release together; the same participant can re-enter and wait in generation1.
Example 2
parties = 3participantIds = [8,9]return = ["WAIT 0","WAIT 0"]Two arrivals do not complete a three-party generation.
Example 3
parties = 1participantIds = [7,7]return = ["RELEASE 0","RELEASE 1"]Every single-party generation releases immediately.
Constraints
1 <= parties <= 1000.0 <= participantIds.length <= 2000.- Participant IDs are integers in
[0,10^9]. - No participant repeats within an incomplete generation.