Intern Coding & Algorithms Interview Questions
Intern coding rounds are where fundamentals win. These coding and algorithms questions were reported from internship interviews, so they cluster around the topics interns actually face: arrays and strings, hash maps, two pointers, stacks and queues, recursion, and the occasional easy graph or tree traversal. The difficulty band is mostly easy-to-medium, and interviewers care as much about clear communication and a working solution as they do about the perfect optimization. If you're prepping for a software engineering internship, this is the focused set to drill — real questions at the real difficulty, most with a step-by-step solution so you can check your reasoning.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Maximize capacity with primary-backup pairing
This question evaluates combinatorial optimization and constrained matching skills, focusing on algorithm design, complexity analysis, and resource-al...
Compute Latencies and Search Grid Path
You are given two coding tasks from an internship interview. Task 1: Compute Message Latency from CSV Logs Two systems, ComputeA and ComputeB, exchang...
Solve array duplicates and two-type subarray
These problems evaluate proficiency with array manipulation, frequency and membership reasoning, and algorithmic analysis of time and space complexity...
Find shortest subarray with at least k distinct
This question evaluates proficiency in array manipulation, frequency counting, and efficient tracking of distinct values within contiguous subarrays, ...
Maximize minimum value after k decrements
This question evaluates array-based optimization skills, resource-allocation reasoning under a fixed decrement budget, and algorithmic complexity anal...
Return a valid task order
This question evaluates understanding of graph algorithms and dependency resolution, testing the ability to produce a valid ordering of tasks and reco...
Implement task queue with insert, delete, execute
Problem: Task manager with insert/delete/execute-next Design a data structure to manage executable tasks. Each task has: - taskId (unique) - priority ...
Implement Prefix Search and Node Removal
This interview included two coding tasks: 1. Implement a prefix-search data structure for strings with two operations: insert(word) and count_with_pre...
Minimize Operations to Balance Shipments
A shop has n item types, where quantity[i] is the positive integer quantity of the i-th item type. The item types must be shipped in two non-empty con...
Design a logger that returns top-K messages
This question evaluates skills in designing in-memory data structures and algorithms for frequency counting and interval querying, including extractin...
Find minimum total range-increment to sort
This question evaluates algorithmic problem-solving skills in array manipulation and optimization, focusing on reasoning about range-increment operati...
Solve tree diameter and grid path problems
You are interviewing for a software engineer / ML intern role and are given the following algorithmic problems. --- Question 1: Longest Path in a Tree...
Board Simulation: Bottom-Insert Pieces with Uniform Row and Column Detection
Board Simulation: Bottom-Insert Pieces with Uniform Row and Column Detection You must simulate a 2-D game board with R rows and C columns. Each cell i...
Compute Fibonacci Numbers
Write a function that returns the nth Fibonacci number. Definitions and requirements: - Use zero-based indexing: fib(0) = 0, fib(1) = 1. - For n >= 2,...
Count closed islands in a grid
This question evaluates grid traversal and connected-component detection skills, focusing on 4-directional adjacency and boundary-condition reasoning ...
Find a valid dependency order
You are given n tasks labeled from 0 to n - 1 and a list of dependency pairs dependencies, where each pair [a, b] means task b must be completed befor...
Implement Cache and Rotate Matrix
Solve the following two independent coding tasks. Task 1: Implement an LRU Cache Design a data structure LRUCache that stores integer keys and integer...
How to maximize rewards with exactly k tasks
You are assigning n independent tasks to two interns. - Each task must be done by exactly one intern. - If intern 1 does task i, you earn reward1[i] p...
Design dynamic weighted random sampling with updates
Problem: Support weighted random sampling with insert/delete Design a data structure that maintains a dynamic set of items, each with a positive integ...
Solve mixed coding tasks from interviews
Solve the following interview-style coding problems (you may choose any programming language unless specified). Provide correct logic and handle edge ...