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."
Detect cycles and order with DFS
You are given a directed graph of package dependencies represented as an adjacency list: Map<String, List<String>> deps where deps[p] lists packages t...
Print Org Chart by Level
This question evaluates the ability to model hierarchical data, work with tree/graph data structures, select traversal strategies, and analyze time an...
Compute nearest bathroom distance for each desk
You are given an m x n grid of characters containing only: - 'B' = bathroom - 'D' = desk - '_' = empty cell From any cell you may move one step up/dow...
Compute an Exact Factorial
Compute an Exact Factorial Implement factorial(n) and return the exact integer value of n!. 0! is defined as 1. The input is always a valid nonnegativ...
Implement Stratified Sampling by Country
This question evaluates understanding of stratified sampling, proportional allocation across groups, reproducible random sampling, data grouping and e...
Bottom-Insertion Connect Game: Detect the First k-in-a-Row Winner
Two players, B and R, take turns dropping pieces onto a board that covers the upper half-plane of an integer grid. Columns are indexed by arbitrary in...
Find conflicting pair using black-box run()
This question evaluates algorithm design and query-complexity reasoning, focusing on efficient search strategies for identifying an interacting pair v...
Compute expected days until no whole pills
This question evaluates understanding of probability and expected value, modeling of state-based stochastic processes (Markov chains), and the ability...
Parse Requests and Compute Balances
This question evaluates input parsing, state management, data validation, and use of basic data structures to track user accounts, friend relationship...
Solve Two Coding Interview Problems
You are asked to solve two independent coding problems. Problem 1: Evaluate Nested Math Expressions Implement a function that evaluates a string expre...
Solve Dependency, Prefix, and Cache Problems
Solve the following three coding problems. Problem 1: Determine Whether All Tasks Can Be Completed You are given numTasks, the number of tasks labeled...
Solve coding and AI-assisted tasks
This set evaluates algorithmic problem-solving across arrays, immutable linked-list interfaces, parent-pointer tree traversal, string validity via min...
Count players reaching end with moving watchers
This question evaluates skills in discrete-event simulation, stateful time-step modeling, and range coverage by moving agents, as well as algorithmic ...
Render Overlapping Rectangles on an ASCII Canvas
Render Overlapping Rectangles on an ASCII Canvas Implement render_canvas(width, height, rectangles). The canvas initially contains spaces and is retur...
Implement Disease and Friend Snapshot Models
You are asked to solve two independent coding problems. Problem 1: Simulate disease spread on a contact graph There are n people labeled 0 through n -...
Solve Five Coding Problems
This problem set evaluates proficiency in core algorithms and data structures, including graph traversal and connected-component identification, array...
Compute Infection Time in a Grid
This question evaluates competence in grid-based graph traversal and simulation of propagation dynamics, focusing on state management, time-step model...
Find Shortest Wiki Click Path
Implement a function that computes the minimum number of clicks needed to navigate from one wiki page to another. You are given two page URIs, start_u...
Implement KNN from Scratch
This question evaluates a candidate's understanding and practical implementation skills for instance-based supervised learning, specifically the k-nea...
Implement Memory-Efficient Document Undo/Redo
This question evaluates data structure design and algorithmic reasoning for implementing memory-efficient undo/redo semantics on a key-value document,...