Find All Anagrams in a String
A medium-tier problem at 52% community acceptance, tagged with Hash Table, String, Sliding Window. Reported in interviews at Snowflake and 7 others.
Find All Anagrams in a String hits your assessment when they want to see if you can track character frequencies efficiently. Snowflake, Bolt, Splunk, and five other companies have asked it. The 52% acceptance rate means half the candidates who see it get stuck, usually on the sliding window part or how to compare frequency maps fast. It's a medium that looks easy until you're live and realize the naive approach times out. This is where StealthCoder becomes your safety net: if the pattern doesn't click during screen share, it surfaces a working solution in seconds while the proctor sees nothing.
Companies that ask "Find All Anagrams in a String"
Find All Anagrams in a String 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 because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround.
Get StealthCoderThe trick is combining a sliding window with hash table frequency tracking. Most candidates try to build a new frequency map at every window position, which is slow. The win is maintaining a single map and updating it as you slide, then comparing only when the window matches the pattern length. The gotcha: you need to either sort both frequency maps or use a canonical form to compare them quickly. Some candidates miss that anagrams must have identical character counts, not just the same characters. The pattern matters across Hash Table, String, and Sliding Window topics because you're operating on substrings while managing character state. If this problem lands in your live OA and you blank on the comparison trick, StealthCoder handles the frequency logic and window mechanics invisibly.
Pattern tags
You know the problem.
Make sure you actually pass it.
Find All Anagrams in a String recycles across companies for a reason. It's medium-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 because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Find All Anagrams in a String interview FAQ
Why does the obvious substring approach fail here?+
Checking every substring against the pattern by sorting or counting is O(n*m*log(m)), which times out on large inputs. The sliding window keeps the window size fixed and updates frequencies incrementally, dropping to O(n) after setup. That's the difference between passing and timing out.
Is this really asked at Snowflake and Splunk?+
Yes. Both are in the reported askers, along with Bolt, Revolut, Yandex, Intuit, Turing, and Databricks. It's common in companies that care about data processing and string manipulation. The 52% acceptance suggests it's a real filter, not a gimme.
What's the best way to compare two frequency maps?+
Sorting both and comparing, or converting to a canonical string representation. The fastest approach is maintaining a single counter and checking if all values are zero after adding and removing characters. Avoid rebuilding the map from scratch at each step.
Does order matter in the pattern vs. the substring?+
No. Anagrams have the same characters in any order. 'listen' and 'silent' are anagrams. Your frequency map captures this automatically by counting occurrences, not tracking position.
How do I avoid off-by-one errors on the sliding window?+
Be explicit about when you add and remove from the window. Add the character at the right edge, then remove from the left once the window exceeds pattern length. Test on a small example first, like pattern 'ab' in 'abab', to verify indices match expected output.
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