Shuffle with Play Tracking | Dataford Interview Questions

Given a list of song IDs, implement shuffle() returning a random unplayed song, play(song_id) marking it played, and reset(), in O(1) time and space

Asked in the Round 2 stage. For grading, implement one function that processes operations in order. shuffle returns an unplayed ID or None, play:<id> returns true or false, and reset returns None. Use a fixed random seed so results are reproducible. Because tracking arbitrary played IDs requires storage, interpret the target as O(1) average time per shuffle and play, with O(n) state and O(n) reset time. Explain why strict O(1) total space is not possible.

Constraints

Song IDs are unique integers.
0 <= len(song_ids) <= 10^4.
0 <= len(operations) <= 10^4.
Each operation is "shuffle", "reset", or "play:<integer>".

Function Signature

def process_song_player(song_ids, operations):

Your question is Shuffle with Play Tracking. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Given a list of song IDs, implement shuffle() returning a random unplayed song, play(song_id) marking it played, and reset(), in O(1) time and space

Constraints

Song IDs are unique integers.
0 <= len(song_ids) <= 10^4.
0 <= len(operations) <= 10^4.
Each operation is "shuffle", "reset", or "play:<integer>".

Function Signature

def process_song_player(song_ids, operations):

Your question is Shuffle with Play Tracking. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.