How should I practice In-Memory Key-Value Store Serialization?

Start by reading the full statement, solve the visible examples, then compare the pattern against related OpenAI phone screen problems in FastPrep.

Is In-Memory Key-Value Store Serialization associated with OpenAI?

FastPrep tags this as a OpenAI phone screen coding practice problem when the problem catalog has that company and stage context.

In-Memory Key-Value Store Serialization

OpenAI● MediumFULLTIMEPHONE SCREEN

Learn

Problem statement

Process an ordered sequence of operations on an initially empty in-memory string key-value store:

["PUT", key, value] stores or overwrites one value and returns "OK".
["GET", key] returns "VALUE:" + value, or "NOT_FOUND".
["SERIALIZE"] returns a deterministic snapshot.
["DESERIALIZE", snapshot] replaces the entire current store with the decoded snapshot and returns "OK".

Encode every key and value as eight uppercase hexadecimal digits containing its 32-bit character length, followed immediately by the characters. A snapshot concatenates encoded key/value pairs in lexicographic key order. The empty store serializes to the empty string. Every deserialization input is a valid snapshot produced by this format.

Return one result for every operation.

Function

processSerializedStore(operations: String[][]) → String[]

Examples

Example 1

operations = [["PUT","b","two"],["PUT","a","one"],["SERIALIZE"],["GET","a"]]return = ["OK","OK","00000001a00000003one00000001b00000003two","VALUE:one"]

Serialization orders key a before key b. Each length occupies exactly eight hexadecimal digits.

Example 2

operations = [["PUT","x:y",""],["SERIALIZE"],["DESERIALIZE","00000001a00000003one"],["GET","x:y"],["GET","a"]]return = ["OK","00000003x:y00000000","OK","NOT_FOUND","VALUE:one"]

Length framing safely carries punctuation and an empty value. Deserialization replaces the old map, so x:y disappears and a maps to one.

Constraints

1 <= operations.length <= 2000.
Keys are non-empty printable ASCII strings of length at most 100; values are printable ASCII strings of length at most 1000.
Every command has the exact fields described above.
Every supplied snapshot is valid, and the total input size is at most 200000 characters.