hashing
5 problems, easiest first. Every one is open — nothing here is locked behind the others.
0 / 5 solved
| Solved | Problem | Topic | Difficulty |
|---|---|---|---|
| Two Sum | hashing | easy | |
| Valid Anagram | hashing | easy | |
| First Unique Character | hashing | medium | |
| Longest Consecutive Sequence | hashing | medium | |
| Group Anagrams | hashing | hard |
Then build one
These problems are one function each. A build challenge is the same ideas assembled into a working thing across several files.
- Hash MapConstruct a high-performance hash map with bucket arrays, modular hashing, collision chaining, and dynamic rehashing.4 stepsjavascript · pythonmedium
- LRU CacheBuild a fixed-size cache that throws away whatever was used least recently.4 stepsjavascript · pythonmedium
- Rate Limiter (Token Bucket)Bound a client to a sustained rate while still tolerating a burst.4 stepsjavascript · pythonmedium
Stuck on the pattern rather than the problem? The hashing lesson walks through it with an animation you can step through.