The Forgetful Machine

A medium Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

medium

Seniority

L5

Problem

A fixed-size in-memory cache holds at most `capacity` key-value entries: `get(key)` returns the stored value or -1 when the key is absent, and `put(key, value)` adds or overwrites an entry, dropping the entry that has gone longest without a read or write whenever an insertion would push the cache past `capacity`. Implement that cache, then implement `LRUCache_driver(capacity, ops)`, which builds one cache of the given capacity, replays each operation in `ops` (either `['get', k]` or `['put', k, v]`), and returns the values produced by the `get` operations in the order they ran.

Summary

It remembers everything, until it does not.

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