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."
Check Root-To-Leaf Target Sums In A Binary Tree
You are given the root of a binary tree and an integer target. Each node contains an integer value. Return true if there is at least one path from the...
Construct connected crop layout and safe paths
Problem A — Construct a garden with connected crop regions You are given an N × M rectangular grid (a garden) that must be fully planted using k crop ...
Reverse Words While Preserving Spaces
Implement a C++ function that reverses the order of words in a string. Assume a word is any maximal sequence of non-space characters, and the input co...
Implement Sparse Matrix Operations
Implement core sparse linear-algebra utilities for interview-style ML code. Tasks: 1. Compute the dot product of two sparse vectors efficiently. 2. Im...
Implement Cache and Count Components
You are asked to solve two independent coding problems in this session, each followed by a short discussion. This mirrors a 60-minute Amazon SDE codin...
Solve Bracket Matching and Tree Width
Solve both coding problems below. Problem 1: Validate Balanced Brackets Given a string s containing only the characters (, ), {, }, [ and ], determine...
Find Minimum Rooms Needed
You are given a list of meeting intervals, where each interval is represented as [start, end) and start < end. Two meetings conflict if their time ran...
Return all valid word-break sentences
Given a string s and a dictionary of strings wordDict, insert spaces into s to form a sentence such that every token is in wordDict. Return all possib...
Reconstruct a binary tree from traversals
Coding: Build a Binary Tree from Two Traversals You are given two integer arrays representing traversals of the same binary tree: - preorder: node ord...
Count closed islands in a grid
Problem You are given an m x n 2D grid representing a map after flooding: - 0 = water - 1 = land An island is a maximal 4-directionally connected comp...
Simulate bubble elimination and maximize common prefix
You are given two independent coding tasks (as in a multi-question OA). Solve each. Task A — Grid “bubble/candy” elimination simulation You are given ...
Merge two sorted linked lists
Given two singly linked lists sorted in ascending order, merge them into one singly linked list that is also sorted in ascending order. Requirements: ...
Return a valid task order
You are given n tasks labeled from 0 to n - 1 and a list of prerequisite pairs prerequisites, where each pair [a, b] means task b must be completed be...
Solve three algorithmic OA problems
This is an online assessment (Codility-style, 150 minutes) consisting of three independent coding problems. Solve each one separately; they do not sha...
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...
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...
Optimize flight and cargo bookings for profit
OptiCargo: make the booking algorithm profitable You are given two streams/lists: - Flights you may attempt to book. Each flight has: - flight_id ...
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...
Count Closed Islands
You are given an m x n binary grid representing terrain after flooding. - 0 = land - 1 = water A land region is an island if its land cells are connec...
Implement a News Publishing System with Topic Subscriptions and Delivery Limits
You are building the core delivery engine for a news publishing service. The service continuously receives news items, stores them, and — whenever a p...