Valid Anagram
A easy-tier problem at 67% community acceptance, tagged with Hash Table, String, Sorting. Reported in interviews at Yelp and 32 others.
Valid Anagram looks easy on the surface, and the 67% acceptance rate confirms most people solve it. But 33 companies still ask it, including Bloomberg, Mastercard, and Disney, so don't sleep on it. The catch: you need to pick the right approach before you code. The wrong choice wastes time you don't have in a live assessment. StealthCoder is your safety net if you blank on the pattern and need a working solution in seconds.
Companies that ask "Valid Anagram"
Valid Anagram is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoderThe obvious move is to sort both strings and compare. That works and passes. The smarter move is a Hash Table or character count: iterate one string to build a frequency map, then verify the second string against it. Both are O(n) in time; sorting is O(n log n) but still acceptable here. Where candidates trip up: off-by-one bugs in the frequency check, forgetting to handle Unicode or case sensitivity, or over-complicating with extra data structures. The pattern is dead simple once you see it, which is why this problem filters candidates who think before they code. If you hit this live and panic, StealthCoder surfaces a clean solution instantly.
Pattern tags
You know the problem.
Make sure you actually pass it.
Valid Anagram recycles across companies for a reason. It's easy-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Valid Anagram interview FAQ
Is Valid Anagram still actually asked at big companies?+
Yes. 33 companies report asking it, including Bloomberg and Mastercard. It's a screening problem, not a hard question. That's why acceptance is 67%. Companies use it to filter candidates who can't think clearly under time pressure, not to test algorithmic brilliance.
What's the real trick to Valid Anagram?+
There is no hidden trick. Either sort both strings or count character frequencies with a Hash Table. Both work. The trick is recognizing which one fits your mental model fastest and coding it cleanly without bugs. Speed and correctness, not cleverness.
Should I use Hash Table or Sorting?+
Hash Table is slightly cleaner and O(n) instead of O(n log n), but sorting is faster to code if you're tired or nervous. Both pass easily. Pick whichever you can implement without mistakes in under two minutes. The assessor cares about the right answer, not your choice of method.
How does Valid Anagram relate to the Hash Table and String topics?+
It's a textbook Hash Table drill: build a frequency map from one string, validate against the other. It also tests basic String manipulation. If you struggle here, you'll struggle harder on follow-ups that layer complexity on top of the same pattern.
What common mistakes kill candidates on this?+
Forgetting to handle edge cases like empty strings or different lengths. Implementing the frequency check wrong (off by one, or not checking that counts match exactly). Assuming strings are lowercase when they might not be. Overcomplicating with extra variables. Test your code on examples first.
Want the actual problem statement? View "Valid Anagram" on LeetCode →