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.
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"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."
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"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."
Solve Four Interview Coding Problems
This question set evaluates algorithmic problem-solving skills including graph traversal and itinerary reconstruction, time-sorted search and binary s...
Solve tree view and parentheses cleanup
Solve the following two algorithm problems. 1. Right-side view of a binary tree Given the root of a binary tree, return the values of the nodes that w...
Move zeros to the front
Given an integer array nums, move all elements equal to 0 to the beginning of the array while preserving the relative order of all non-zero elements. ...
Design stack with O(1) minimum query
This question evaluates understanding of stack-based data structures, constant-time operation constraints, and handling edge cases such as empty queri...
Extract stream prefix before stop token
This question evaluates streaming string processing, incremental substring detection across chunk boundaries, and memory-efficient algorithm design fo...
Build a CSV Query Engine
This question evaluates proficiency in text parsing, data modeling, and implementing in-memory query semantics, including CSV parsing rules, type infe...
Find minimum subarray length with k distinct integers
Given an integer array arr and an integer k, find the minimum length of a contiguous subarray that contains exactly k distinct integer values. Return ...
Implement calculator and graph connectivity
Answer the following coding problems: 1. Implement an arithmetic expression evaluator. Given a string containing non-negative integers, spaces, +, -, ...
Solve Three Algorithmic Problems
Three coding questions were mentioned: 1. Second-largest distinct permutation Given an array of integers that may contain duplicates, consider all ...
Sort a nearly sorted array
Given an array of length \(n\) in which every element is at most \(k\) positions away from its location in the fully sorted order, design an algorithm...
Return valid task order from prerequisites
You are given N tasks labeled 0..N-1 and a list of directed dependency pairs [(a,b), ...] meaning task a must be done before task b. 1) Return one val...
Implement store, evaluator, and parser
This question evaluates implementation skills in data structures and algorithms, covering time-based versioning and TTL in an in-memory key-value stor...
Return a Package Build Order
You are given an API: `python get_dependencies(package) -> list[str] ` It returns the direct dependencies of a given package. If package A depends on ...
Solve Two Grid Search Problems
This question evaluates proficiency in graph traversal on grids, specifically competencies in identifying connected components and modeling propagatio...
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 ...
Find shortest jumps in circular array
You are given a circular array arr of length n. From index i, you may jump exactly arr[i] steps either to the left or to the right (wrapping around th...
Normalize a file path
Given an absolute Unix-style file path as a string, return its canonical normalized form. Rules: - The input always starts with /. - A single . means ...
Solve 15 common interview problems
Below are fifteen independent coding problems commonly discussed in software engineering interviews. For each one, write an efficient algorithm and be...
Maximize protected population with one-step guard shifts
There are n cities in a line (1-indexed). You are given: - population[1..n]: population of each city - unit: a binary string of length n, where unit[i...
Maximize weighted subsequence pairs with wildcards
You are given a string s of length n consisting only of characters '0', '1', and '!'. Each '!' can be replaced by either '0' or '1'. For the final bin...