Coding & Algorithms Interview Questions
Practice 3,469 real Coding & Algorithms interview questions for 2026. Covers companies like Meta, Amazon, Google, Uber, and Microsoft. Real questions from actual interviews with detailed solutions — ideal for focused interview preparation. Coding & Algorithms interview questions are the single most common technical gate for software engineering roles and are used to evaluate problem framing, algorithm selection, complexity trade-offs, correctness, edge-case reasoning, and clear communication under time pressure. Expect this category to appear in early technical screens and repeatedly across onsite loops at companies that weight it heavily (notably Meta, Google, and Amazon). Interviews will test arrays and strings, trees and graphs, dynamic programming, hashing and two‑pointer techniques, and the candidate’s ability to test and optimize code in a shared editor. Prepare with timed mock interviews, practice in the same editor you’ll use live, and build a progressive schedule that moves from fundamentals to medium/hard problems; typical candidates invest several weeks to a few months of focused practice depending on seniority and target company.
"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."
Implement topological sort and tree boundary traversal
You are given two separate coding tasks. Problem A — Order courses with prerequisites You have n courses labeled 0..n-1 and a list of prerequisite pai...
Solve tree, array, and maze tasks
This set of problems evaluates proficiency in algorithms and data structures, covering binary tree diameter computation, array optimization for maximu...
Solve scheduling and tree path problems
This set evaluates interval scheduling and constrained optimization for weighted, at-most-K selection, tree structure manipulation and subtree effects...
Maximize concatenation length with unique chars
This question evaluates understanding of string manipulation, set-based uniqueness constraints, and combinatorial subset selection for maximizing conc...
How to find the cheapest flight within K stops
This question evaluates understanding of graph algorithms and constrained shortest-path modeling, focusing on reasoning about weighted directed edges,...
Compute final prices with next smaller discount
You are given an integer array prices of length n, where prices[i] is the original price of the i-th item. For each item i, find the first index j > i...
Implement LRU/LFU cache with custom eviction
This question evaluates proficiency in cache design and data-structure implementation, focusing on eviction policies (LRU, LFU), metadata tracking for...
Determine balanced k values in a permutation
You are given a permutation p of the integers 1..n. For a number k (where 1 <= k <= n), call k balanced if there exists a contiguous subarray p[l..r] ...
Find minimum moves to solve the 15-puzzle
This question evaluates understanding of state-space search, heuristic reasoning, and solvability analysis for combinatorial sliding puzzles, testing ...
Implement idempotent request handling with idempotency keys
This question evaluates understanding of idempotency semantics, idempotency-key handling, concurrency control, synchronization, and in-memory TTL-base...
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 ...
Simulate 2048 and pack board into uint64
Problem: 2048 move simulation + board compression You are implementing part of the 2048 game on a fixed 4×4 grid. Part A — Simulate a move Given a 4×4...
Design iterator for sorted union
This question evaluates algorithmic thinking and iterator-based streaming skills, focusing on merging strictly increasing inputs and deduplicating res...
Extend a BFS maze solver stepwise
This question evaluates proficiency in grid-based graph traversal and pathfinding, covering BFS mechanics, stateful reachability with keys and doors, ...
Solve maze tasks and compute shortest routes
This multi-part question evaluates proficiency in grid-based pathfinding and shortest-path reasoning, debugging and incremental code extension, handli...
Group points by distance threshold
This question evaluates understanding of geometric graph construction and connectivity, computational geometry concepts such as Euclidean distance, an...
Can you visit all rooms and score parentheses?
Problem 1: Visit all locked rooms with keys There are n rooms labeled 0..n-1. All rooms are locked except room 0. - When you enter room i, you find a ...
Minimize operations to reduce integer to zero
This question evaluates algorithmic problem-solving and integer-manipulation skills, specifically assessing the ability to reason about operation coun...
Count subarrays with sum equals k
This question evaluates a candidate's competency in array algorithms and reasoning about contiguous subarray sums, including correct handling of negat...
Answer suffix maximum-frequency queries
This question evaluates algorithm design skills and array-processing competency for answering repeated queries efficiently, focusing on time and space...