Count Balanced Clilps
Reported by candidates from TikTok's online assessment. Pattern, common pitfall, and the honest play if you blank under the timer.
TikTok's October OA included a problem on balanced clips, and it's testing whether you know the canonical balanced-parentheses pattern. You're likely dealing with a string of brackets or delimiters that need to form valid nested pairs. The trick isn't the logic, it's recognizing that this is a classic stack problem in disguise. If you blank on the approach during the live OA, StealthCoder will surface the pattern instantly so you can code without panic.
Pattern and pitfall
Balanced clips almost certainly means you're counting valid configurations or checking validity of nested structures. The standard approach uses a stack to track opening symbols and match them with closing ones. You iterate through the input, push opens onto the stack, and pop when you see a close. If the stack is empty at the end and never underflowed, it's balanced. Common pitfall: candidates try to count matches without structure, losing track of nesting order. The real challenge is usually the edge cases: empty input, odd-length input, mismatched pairs. During the OA, if you hit a wall on the algorithm, StealthCoder acts as your safety net by confirming the stack-based pattern so you can execute cleanly.
If this hits your live OA and you blank, StealthCoder solves it in seconds, invisible to the proctor.
You can drill Count Balanced Clilps cold, or you can hedge it. StealthCoder runs invisibly during screen share and surfaces a working solution in under 2 seconds. The proctor sees the IDE. They don't see what's behind it. Built by an Amazon engineer who would have shipped this the night before his JPMorgan OA if he'd had it.
Get StealthCoderRelated leaked OAs
This OA pattern shows up on LeetCode as valid parentheses. If you have time before the OA, drill that.
You've seen the question.
Make sure you actually pass TikTok's OA.
TikTok reuses patterns across OAs. Built by an Amazon engineer who would have shipped this the night before his JPMorgan OA if he'd had it. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Count Balanced Clilps FAQ
Is this just checking if clips are balanced, or do I need to count something?+
The title says 'Count', so you're likely counting the number of balanced substrings or pairs, not just validating. Start by understanding whether you count clips as you go or enumerate all valid balanced configurations. Read the problem statement carefully for examples.
Do I need dynamic programming for this?+
Not necessarily. A stack gets you through most balanced-string problems in O(n) time. DP shows up if the problem asks for counting all possible ways or optimal selections, but stack-first is the safer bet on a time-crunched OA.
What if the input has mixed bracket types?+
Stack still works. Push opens and store their type. When you pop, check that the close matches the type of the most recent open. Mismatches mean invalid. Track all matched pairs and sum at the end if counting total clips.
How do I handle edge cases fast?+
Empty string returns 0 clips. Odd-length strings can't be fully balanced, so max clips is floor(length/2). If all opens or all closes, 0 balanced clips. Run these checks first to avoid wasted iterations.
Should I memorize a template for this?+
Yes. Stack-based bracket matching is asked constantly. Know: push on open, pop and validate on close, check stack empty at end. Practice it on a real problem tonight so your fingers know the motions during the OA.