Coding & Algorithms Interview Questions
Practice 3,013 real Coding & Algorithms interview questions for 2026. Coding & Algorithms interview questions for top tech firms like Meta, Amazon, Google, Uber, and TikTok — real questions from actual interviews with detailed solutions — to power your interview preparation. This collection is sharply focused on algorithmic patterns (arrays, strings, sliding windows, trees/graphs, dynamic programming, greedy, two-pointers, and hashing), clean, review-ready code, and the explanation skills that distinguish hires. In 2026 expect familiar medium-to-hard problems plus newer twists: AI-enabled or multi-file coding rounds at some companies, more emphasis on explainability and edge-case reasoning, and occasional real-world performance constraints (streaming, concurrency, memory limits). Interviewers evaluate problem framing, algorithm choice, complexity trade-offs, test-case thinking, and communication under time pressure. Best prep mixes pattern-based practice, timed mock interviews, code-review style polishing, and rehearsed explanations of complexity and tradeoffs. Focus your last-mile prep on writing correct, readable code quickly and on explaining why your solution is robust and efficient for production scenarios.
"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."
Compute subtree sums with tree DFS
You are given an undirected tree with n nodes labeled 1..n and n-1 edges. The tree is rooted at node 1. Each node i has an integer value val[i]. Retur...
Maximize 1D deliveries within distance and minimize total distance
You are given positions on a 1D line: - people: an array of N integers (positions of people) - shops: an array of M integers (positions of milk-tea sh...
Solve scheduling and tree path problems
You are given three separate coding problems (asked across two rounds). For each, write a function that returns the required output. Problem 1: Max cr...
Merge intervals and design rating APIs
Problem 1: Merge overlapping intervals You are given a list of closed intervals intervals, where intervals[i] = [start_i, end_i] and start_i <= end_i....
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 sequential and parallel URL requests
You are given a list of URL strings. For each URL, send an HTTP GET request and return the responses. Output format Return a list of objects: - url: t...
Find Earliest Train Route
You are given a discrete train timetable and need to find a valid route through the train network. Each train has an itinerary represented as a sequen...
Implement array rotations and CSV keyword search
Problem A — Rotate an array left/right by k You are given an integer array nums of length n and an integer k. 1. Implement rotateLeft(nums, k) that re...
Solve several streaming, DAG, and DP tasks
You were asked multiple algorithmic questions. 1) Streaming longest subarray with average S You receive an infinite stream of integers (can be positiv...
Solve Grid Path and Unique Substring
You are given two independent coding problems. For each problem, provide an implementation and analyze the time and space complexity. Problem 1: Find ...
Compute shipping cost with tiered pricing
You are implementing a shipping-cost calculator for an e-commerce checkout. An order contains multiple line items. Each line item has: - country: str ...
Implement a persistent sharded key-value store
Problem Implement a simple key–value store that persists data on disk. You must store the data in fixed-size shards, where each shard is saved in one ...
Choose container set to minimize waste
Question A pharmaceutical company is packaging liquid medicine for shipment. Each customer order has a required volume. The company can choose exactly...
Count Cross-Group Employee Pairs
You are given n employees labeled from 0 to n - 1 and a list of relationships relations, where each pair [a, b] means employees a and b belong to the ...
Solve two interview coding problems
This interview included two coding tasks: 1. Currency conversion graph You are given a set of directed currency exchange rates, for example: - C...
Find minimum tanks to cover all houses
You are given a string S representing a street: - 'H' = a house - '-' = an empty plot where you may place a water tank A house is considered covered (...
Find Earliest Fully Connected Time
You are given n people labeled 0 to n - 1 and a list of friendship logs. Each log has the form (timestamp, personA, personB, action), where action is ...
Implement feedback for word guessing game
You are implementing the core logic for a simple word-guessing game. There is: - A dictionary of valid words: a list of distinct lowercase strings, al...
Design a bank with scheduled payments and merges
Design an in-memory banking service that supports the following operations: ( 1) CreateAccount(accountId), ( 2) Deposit(accountId, amount), ( 3) Trans...
Determine equality of arbitrarily nested sets
Implement a function that determines whether two arbitrarily nested sets are equal. Sets are unordered and contain no duplicates; elements can be inte...