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 an LRU Cache
Problem: LRU Cache (LeetCode 146) Design and implement a Least Recently Used (LRU) Cache that supports the following operations in average O(1) time. ...
Implement an unbiased array shuffle
Implement an unbiased array shuffle Implement an in-place function shuffle(arr) in JavaScript that returns a uniformly random permutation of the input...
Compute peak busy dashers with overlaps
You are given delivery logs as (dasherId, startTime, endTime) with integer times, where endTime is exclusive. A single dasher may accept multiple orde...
Place items into earliest fitting bins
Place items into earliest fitting bins You are given k items with sizes items[0..k-1] and n bins with initial capacities caps[0..n-1]. Process items i...
Find LCA in a BST
Find LCA in a BST Given the root of a binary search tree and two keys p and q, return the value of their lowest common ancestor (the deepest node whos...
Minimize adjacent-color assignment cost
Minimize adjacent-color assignment cost You are given H linear items (e.g., houses) and an H×C cost matrix where cost[i][c] is the cost of assigning c...
Solve three C++ algorithmic tasks
Solve three C++ algorithmic tasks Solve the following three C++ algorithmic tasks. For each, implement an efficient function and state time and space ...
Find odd-frequency element with O(1) space
You're given an integer array where exactly one value appears an odd number of times and all other values appear an even number of times. Implement a ...
Compute rolling standard deviation in O(n)
Compute rolling standard deviation in O(n) Given an array of numbers and a window size k, compute the rolling standard deviation for every contiguous ...
Solve array merge and tree flattening problems
Solve array merge and tree flattening problems 1) Given two sorted arrays, merge them into a single sorted array. Provide both an in-place approach (w...
Maintain top N payers
Maintain top N payers Implement topNPayers(n) that returns the n accounts with the highest cumulative outgoing payment amounts as strings formatted "{...
Count subarrays with odd zero count
Count subarrays with odd zero count Given an integer array nums, return how many contiguous subarrays contain an odd number of zeros. Provide an O(n) ...
Design a snapshotable key-value store
Design a snapshotable key-value store Design and implement a snapshotable key–value map supporting the following APIs: - S(key, value): set the curren...
Count expressions reaching a target sum
Count expressions reaching a target sum Given an array of non-negative integers nums and an integer target T, assign either a + or − sign to each numb...
Fix a BST with two misplaced keys
Fix a BST with two misplaced keys You are given the root of a binary search tree in which exactly two nodes’ keys were accidentally swapped. Restore t...
Find users with access to all cameras
Given entities and relationships (user, owns, camera), (user, belongs_to, group), (group, owns, camera), and (group, belongs_to, group) where groups c...
Weighted LRU Cache: Capacity Counted by Item Quantity
Design a variant of the classic least-recently-used (LRU) cache. In the classic version, the capacity limits the number of items stored. In this varia...
Solve shortest and label-similar paths
Solve shortest and label-similar paths Part A — Unweighted shortest path: You are given an undirected, unweighted graph with vertices labeled 0..n-1 a...
Compute optimal locker placement with obstacles
Compute optimal locker placement with obstacles Given house coordinates H = {(xi, yi)} and tree coordinates T = {(xj, yj)} on a 2D integer grid, choos...
Design a streaming median structure
Design a streaming median structure Design a data structure for a number stream that supports: add(num: int) in O(log n) time and median() -> float in...