Solution: Time Based Key-Value Store

Explore how to implement a custom data structure that supports storing and retrieving multiple values per key at various timestamps. Learn to optimize the retrieval using binary search, handle edge cases, and understand the trade-offs in time and space complexity for an efficient solution.

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Statement
Solution
- Naive approach
- Optimized approach using binary search

Statement

Implement a data structure that can store multiple values of the same key at different timestamps and retrieve the key’s value at a certain timestamp.

You’ll need to implement the TimeStamp class. This class has the following functions:

Init(): This function initializes the values dictionary and timestamp dictionary.
Set Value(key, value, timestamp): This function stores the key and value at any given timestamp.
Get Value(key, timestamp): This function returns the value set for this key at the specified timestamp.

Note: When a query requests the value of a key at a timestamp that isn’t recorded, return the value corresponding to the most recent timestamp before the query’s timestamp. If there are no timestamps before the query’s timestamp, return an empty string.

Constraints:

$1 \leq$ key.length, value.length $\leq 20$
key and value consist of lowercase English letters and digits.
$1$

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