Dynamic Dictionary Sampling Script | Dataford Interview Questions

Write a Python script to perform dynamic insertion, removal, and unbiased random sampling on dynamic dictionary structures.

Implement dynamic_dictionary(operations, seed) using operations ["insert", key, value], ["remove", key], and ["sample"]. Return one result per operation: insertion returns whether the key was new, removal returns whether the key existed, and sampling returns a uniformly random current key or None when empty. Updating an existing key must not create a duplicate sampling entry. Use seed only to make tests reproducible.

Example: [["insert", "a", 1], ["insert", "b", 2], ["remove", "a"], ["sample"]] with seed 4 returns [true, true, true, "b"].

Constraints: At most 1,000 operations, string keys are unique dictionary keys, and values are arbitrary Python values.

Constraints

1 <= len(operations) <= 1,000
Each operation is either ["insert", key, value], ["remove", key], or ["sample"]
Keys are hashable and values are arbitrary Python values
Sampling must be uniform over active keys
Updating an existing key does not add another sampling entry

Function Signature

def dynamic_dictionary(operations, seed):

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