Remove Comments
A medium-tier problem at 39% community acceptance, tagged with Array, String. Reported in interviews at Hudson River Trading and 1 others.
Remove Comments is a medium-difficulty string parsing problem that hits your OA if you interview at Hudson River Trading or Uber. It's deceptively simple: given source code with single-line and block comments, strip them out and return the cleaned code. The acceptance rate sits at 39%, which means most candidates who see it either mishandle edge cases around comment boundaries or don't account for strings that contain comment syntax. If this problem lands in your assessment and you blank on the state machine pattern, StealthCoder solves it invisibly in seconds.
Companies that ask "Remove Comments"
Remove Comments 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 for the engineer who has done the work but might still blank with a webcam pointed at him.
Get StealthCoderThe trap is thinking you can just scan for '//' or '/*' and remove everything after. Real difficulty comes from distinguishing comment markers inside quoted strings (which don't start comments) from actual comment delimiters. The solution uses a finite state machine: track whether you're inside a block comment, a line comment, or a string. Character by character, you decide what to keep and what to skip. Most candidates either miss the string-handling requirement entirely or mess up the transition logic between states when a line comment ends. The String and Array topics confirm you're building this with character iteration and output accumulation. When you hit the live OA, the gaps in your state machine logic become obvious only after test case failures. StealthCoder hedges that gap by surfacing a bulletproof implementation the moment you recognize the pattern.
Pattern tags
You know the problem.
Make sure you actually pass it.
Remove Comments 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. Made for the engineer who has done the work but might still blank with a webcam pointed at him. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Remove Comments interview FAQ
Is this really asked at Uber and Hudson River Trading?+
Yes. Both companies appear in the historical ask data for this problem. It's a genuine assessment question, not a theoretical exercise. Medium difficulty aligns with mid-level SDE screening, so you could see it in phone rounds or online assessments.
Why does the acceptance rate sit at 39%?+
Most failures come from incomplete edge case handling. Candidates handle the happy path (clean comments) but break on strings containing '//' or '/*', or they miscalculate where a block comment ends when multiple markers exist. State machine discipline is non-obvious under time pressure.
What's the main trick I'm missing if I fail test cases?+
You're likely not tracking whether you're inside a string literal. In source code, a single-quoted or double-quoted string can contain '//' or '/*' without starting a comment. You need a separate state for 'inside string' that overrides comment parsing logic.
How does this relate to String and Array topics?+
String because you're parsing character by character and identifying syntax boundaries. Array because you're likely iterating over the input as a character array or list and building an output array/list of kept characters, then joining back to a string.
Should I memorize this or understand the pattern?+
Understand the state machine pattern. Build a small mental model: what states can you be in (normal/block-comment/line-comment/string), and when do you transition between them. That pattern solves similar parsing problems in real codebases.
Want the actual problem statement? View "Remove Comments" on LeetCode →