Solution: Time Based Key-Value Store

Explore how to design a time-based key-value store in JavaScript that stores multiple values per key with timestamps. Understand how to efficiently set and get values, leveraging binary search to retrieve the most recent value before a given timestamp. This lesson covers the implementation details, time and space complexity, and practical tradeoffs in designing custom data structures for coding interviews.

We'll cover the following...

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.
$1$

...