Consecutive Characters
A easy-tier problem at 60% community acceptance, tagged with String. Reported in interviews at Goldman Sachs and 0 others.
Consecutive Characters is an easy string problem that's deceptively simple on the surface but trips up candidates who overthink it. You're given a string and need to find the longest run of identical consecutive characters. It shows up in assessments at places like Goldman Sachs. The problem looks trivial until you're live, stressed, and suddenly second-guessing whether you need a hash map or a state machine. You don't. StealthCoder surfaces the clean solution in seconds if you hit a mental block during the assessment.
Companies that ask "Consecutive Characters"
Consecutive Characters 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 pattern is a single linear pass with a counter and a max tracker. Iterate through the string, increment a counter when the current character matches the previous one, reset when it changes, and keep track of the highest count you've seen. Common mistake: overcomplicating it with extra data structures or trying to preprocess the string. The obvious approach is the right one here. Another trap is off-by-one errors in your final count if you don't handle the loop exit correctly. String problems at this level test whether you can write clean, correct code without gold-plating it. If you've drilled basic string iteration, this is a warmup. If you blank on the loop logic during a live OA, StealthCoder runs invisibly and gives you a working solution so you can move on.
Pattern tags
You know the problem.
Make sure you actually pass it.
Consecutive Characters 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. 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.
Consecutive Characters interview FAQ
Is Consecutive Characters actually asked in real interviews?+
Yes. It's reported from Goldman Sachs and has a 60% acceptance rate, so it's not obscure. It's the kind of easy problem companies use early in an assessment loop to verify you can write bug-free code under time pressure, not necessarily to measure algorithm knowledge.
What's the trick to this problem?+
There isn't one. That's the trick. One pass, two pointers or a counter, track the max. If you're searching for a clever insight, you're overthinking it. The mental block usually comes from expecting it to be harder than it is.
Do I need a hash map or dictionary?+
No. You're not counting distinct characters or storing frequencies. You're tracking consecutive runs of the same character. A single integer counter and a max variable are all you need. Anything else adds complexity and risk of bugs.
What are common mistakes on this problem?+
Off-by-one errors when the longest run is at the end of the string. Forgetting to compare the current character to the previous one. Resetting your counter at the wrong time. Testing with examples like 'aaa' and 'aaaa' catches most of these.
How does Consecutive Characters fit into string interview prep?+
It's a baseline. If you can write this cleanly in under 2 minutes, you're solid on string iteration and basic state tracking. It builds confidence before tackling harder string problems like pattern matching or substring algorithms.
Want the actual problem statement? View "Consecutive Characters" on LeetCode →