Coding questions
NTT Data Online Assessment
Overview
The NTT Data online assessment (OA) is the first round of fresher hiring, and clearing it shortlists you for interviews, not an offer. Format (candidate-reported): ~90 min aptitude + technical + 1-2 coding. Full process: OA → Technical → HR (GD/AMCAT on some campus drives). Eligibility: 60% or 6.0+ CGPA throughout 10th, 12th, graduation; no active backlogs; gap ≤ ~2 years.
Detailed public write-ups on the NTT Data online test are still hard to find.
What public reports and campus notices usually say (still verify officially):
| Item | Working note |
|---|---|
| Online test name | NTT Data Online Assessment |
| Focus areas (metadata) | DSA, aptitude |
| Languages (metadata) | C, C++, Java, Python. |
| Reported round names | Online Assessment (90 min) → Technical Interview → HR. 2-3 weeks total. |
Practice drills
Coding Q1: Stack with min
Problem: Design a stack that supports push, pop, top, and getMin in average O(1) time.
Approach: Keep a parallel min-stack (or store pairs). When pushing, also push the new minimum. When popping, pop both stacks.
Complexity: O(1) per operation amortized
NTT Data tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q2: Maximum subarray sum (Kadane)
Problem: Given an integer array, find the contiguous subarray with the largest sum and return that sum. Example: [-2,1,-3,4,-1,2,1,-5,4] → 6 (from [4,-1,2,1]).
Approach: Keep a running sum. If the running sum drops below 0, reset it to 0 before taking the next element (or track the best ending-here value). Track the global maximum as you scan once from left to right.
Complexity: O(n) time, O(1) extra space
NTT Data tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q3: Reverse a string in place
Problem: Given a mutable character array representing a string, reverse it in place without allocating another array of the same size.
Approach: Use two pointers at the start and end. Swap characters, then move inward until the pointers meet. Watch empty and single-character inputs.
Complexity: O(n) time, O(1) extra space
NTT Data tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q4: Check prime
Problem: Write a function that returns true if n is prime and false otherwise. Handle n < 2 correctly.
Approach: Return false for n < 2. Trial-divide from 2 to floor(sqrt(n)). If any divisor divides n evenly, it is composite; otherwise prime.
Complexity: O(√n) time
NTT Data tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
What to do next
- Open the official careers page or your college placement email for NTT Data
- Search GeeksforGeeks + Reddit for
NTT Data interview experience - Use Faceprep / PrepInsta only if they match your placement email