Count Anagrams
A hard-tier problem at 35% community acceptance, tagged with Hash Table, Math, String. Reported in interviews at MathWorks and 0 others.
Count Anagrams hits you when you least expect it. You're given strings and need to count how many anagrams exist in a dataset, but the naive approach tanks on large inputs. It's been asked at MathWorks and appears in harder prep tracks. The trick isn't just identifying anagrams, it's counting them efficiently without exploding your runtime. If you blank on the combinatorics layer during your live OA, StealthCoder surfaces the working solution invisible to the proctor, buying you the minutes you need to move on.
Companies that ask "Count Anagrams"
Count Anagrams 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. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE.
Get StealthCoderThe core problem demands you group anagrams, then count pair or group combinations. Most candidates sort characters or use frequency maps to identify anagrams, which is solid. The wall comes when you realize you also need combinatorics: given n anagrams, how many distinct pairs or subsets exist. The math isn't hard once you see it, but it's easy to miss under pressure. Hash Table groups strings by their sorted form or character frequency. Then Combinatorics and Counting take over, you're computing C(n, 2) or similar for each group. The acceptance rate sits at 35 percent, meaning most submissions fail either the grouping or the counting phase. When you hit this live and the combinatorics piece doesn't click, StealthCoder runs silently and hands you the exact formula and code structure, letting you paste and move forward.
Pattern tags
You know the problem.
Make sure you actually pass it.
Count Anagrams recycles across companies for a reason. It's hard-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. Made by a working Amazon engineer who got tired of watching qualified friends bomb OAs they'd solve cold in an IDE. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Count Anagrams interview FAQ
Is this problem really about both hashing and math?+
Yes. Hash Table gets you to group anagrams fast. Then Combinatorics and Counting kick in to compute the answer from those groups. Missing either piece tanks your solution. The input data confirms both topics are core to the problem.
Why is the acceptance rate so low at 35 percent?+
Most candidates nail the anagram grouping but stumble on the counting math. They either forget the formula, implement it wrong, or don't realize they need it at all. It's a two-step problem where step two is non-obvious under interview pressure.
What's the trick that separates passing from failing?+
Realizing you can't just iterate and count manually. You need the closed-form combinatorial formula. Once you see that, the code is short. The trick is knowing when to switch from iteration to math, which most candidates don't do in real time.
Does MathWorks really ask this, and is it their only coding problem?+
Yes, MathWorks has asked it. It's the only reported company asking this problem in the dataset, which suggests it's either new, niche, or specific to their hiring loop. That doesn't mean it's rare overall, just that it's less common in public records.
How do I prepare if I've never seen the combinatorics angle?+
Drill anagram grouping first with Hash Table and String problems. Then do a few Combinatorics problems on counting pairs and subsets. When you combine them, this problem clicks. If you run out of time, StealthCoder runs during the live OA and solves it instantly.
Want the actual problem statement? View "Count Anagrams" on LeetCode →