Daily Coding Problem: Problem #1457 [Hard]

Good morning! Here's your coding interview problem for today.

This problem was asked by Google.

Implement an LFU (Least Frequently Used) cache. It should be able to be initialized with a cache size n, and contain the following methods:

• set(key, value): sets key to value. If there are already n items in the cache and we are adding a new item, then it should also remove the least frequently used item. If there is a tie, then the least recently used key should be removed.
• get(key): gets the value at key. If no such key exists, return null.

Each operation should run in O(1) time.

Upgrade to premium and get in-depth solutions to every problem, including this one. Since you were referred by one of our affiliates, you'll get a 10% discount on checkout!

If you liked this problem, feel free to forward it along so they can subscribe here! As always, shoot us an email if there's anything we can help with!

Practice makes perfect. Book a mock interview with a FAANG-level interviewer today from our friends at Exponent (10% off!).

System design interviews are becoming more popular in SWE interviews. Here's how to prepare.

No more? Snooze or unsubscribe.