CTC coding interview
questions, leaked.
1 problems reported across recent CTC interviews. Top patterns: array, dynamic programming, greedy. The list below is what most reported candidates actually saw, plus the honest play if you can't grind all of it.
CTC's coding assessment is lean: one medium problem that hits array, dynamic programming, and greedy logic at once. Best Time to Buy and Sell Stock II is the only reported problem, which means prep is narrowly focused. You're not grinding a hundred variations. You're mastering one pattern that CTC clearly cares about. If you can handle buy-sell logic with multiple transactions, you can pass their OA. If you blank on the greedy insight mid-assessment, StealthCoder surfaces the solution invisibly while you're screen-sharing.
Top problems at CTC
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Best Time to Buy and Sell Stock II | MEDIUM | 100.0 | 70% | Array · Dynamic Programming · Greedy |
Frequencies derived from public community-tagged interview reports. Click a row to view on LeetCode.
You have a week, maybe less. You can't out-grind the list above. StealthCoder runs invisibly during the actual CTC OA. The proctor cannot see it. Screen share cannot detect it. Built because the OA filter rejects engineers who'd pass the on-site. That's a broken filter. This is the workaround.
Get StealthCoder- array1 · 100%
- dynamic programming1 · 100%
- greedy1 · 100%
This isn't a broad assessment. CTC is testing whether you can recognize that a greedy approach beats dynamic programming on this specific problem. Array manipulation is the surface; greedy is the insight. You need to understand why you can capture every upswing without tracking state. Most candidates over-engineer this with DP tables. The win is realizing you don't need them. Study the greedy pattern first, then see how DP would work so you understand why greedy dominates. Since there's only one reported problem, your hedge is StealthCoder. If a curveball lands on the OA, you have real-time backup.
Companies with similar patterns
If you prepped for CTC, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass CTC.
Memorizing every problem above in a week is a fantasy. StealthCoder is the hedge: an AI overlay that's invisible during screen share. It reads the problem on screen 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.
CTC interview FAQ
Is one problem enough to represent CTC's interview?+
One problem in the dataset suggests either CTC's OA is minimal, or it's early data. Either way, master Best Time to Buy and Sell Stock II completely. Know the greedy solution, the DP alternative, and trade-offs between them. Treat it as the core signal they're measuring.
Should I study dynamic programming or greedy first for this?+
Greedy first. CTC's problem rewards the greedy insight: sum all positive differences. Then learn DP so you understand why greedy is superior here. That depth of understanding is what separates pass from fail on their OA.
What if CTC's live assessment has a different problem?+
You'll face array or greedy logic. One problem isn't statistical proof of the full loop. Prepare broadly for greedy and array patterns, and know that StealthCoder is your real-time safety net if an unfamiliar variant appears during screen share.
How long should I spend prepping for a one-problem assessment?+
Two to three focused sessions. Problem-solve it from scratch, then study the greedy proof. Trace the algorithm by hand. If you can explain why greedy works here, you're ready. Don't over-prepare; you'll hit diminishing returns fast.
Is medium difficulty the right baseline for CTC?+
Yes. Medium means CTC isn't testing advanced DP or complex state machines. They're testing pattern recognition and clean implementation. Focus on clarity and correctness over optimization tricks.