Coding & Algorithms Interview Questions
Practice 3,429 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."
Find k most frequent elements, discuss O(n)
Find k most frequent elements, discuss O(n) Given an integer array nums of length n and an integer k (where 1 ≤ k ≤ the number of distinct values in n...
Implement cluster status tracker
Implement a cluster status tracker. Design a class with methods: update(nodeId, status, timestamp) to record node status updates that may arrive out o...
Solve frequency sort and all-pairs sum
Solve frequency sort and all-pairs sum Task 1 — Frequency-based string reorder: Given a string s containing ASCII characters, return a new string whos...
Stone Pile Doubling Game: Can One Pile Be Emptied?
You are given two piles of stones containing a and b stones respectively (both piles start non-empty). You repeatedly apply the following move: - Let ...
Implement LRU and target-sum combinations
Implement LRU and target-sum combinations Design and implement the following: 1) An in-memory cache with Least Recently Used (LRU) eviction supporting...
Produce asymmetric side views of a binary tree
Produce asymmetric side views of a binary tree Given a binary tree, output two sequences: ( 1) Left-bottom-up view: for each depth, the first node vis...
Remove adjacent duplicate groups repeatedly
Remove adjacent duplicate groups repeatedly Given a string s, repeatedly delete any maximal contiguous group of identical characters whose length is a...
Transform tree with subtree sum mapping
Transform tree with subtree sum mapping You are given the roots of two complete binary trees T1 and T2 that have identical structure (same shape and n...
Determine if robot path is bounded
Determine if robot path is bounded A robot starts at (0, 0) facing North on an infinite grid. It executes a string s consisting of 'G' (move forward 1...
Find shortest subarray meeting target sum
Find shortest subarray meeting target sum Given an integer array nums (values may be negative) and an integer T, return the length of the shortest non...
Compute sum of minima with removals
Compute sum of minima with removals You are given an array weights[0..n-1] of positive integers representing product weights in a line. Repeat until n...
Solve median extremes and segment flips
Solve median extremes and segment flips Part A — Sliding-window median extremes: - Input: an integer k (1 ≤ k ≤ n) and an array nums of length n. - Fo...
Explain hash maps and solve array intersection
1) Explain the internal implementation of a hash map: underlying array/bucket layout, hash function choice, collision resolution strategies (separate ...
Find minimum shuttle transfers
Find minimum shuttle transfers You are given a collection of shuttle loops, each represented by a list of stop IDs that the loop visits in perpetuity....
Find and remove duplicate files
Given a directory tree that may not fit in memory, detect and optionally remove duplicate files. Define the algorithm, including how you handle very l...
Validate a Binary Tree Built from Directed Edges
Validate a Binary Tree Built from Directed Edges You are given a list of directed edges. Each edge is a pair (parent, child) of positive-integer node ...
Count the Days Between Two Dates
Count the Days Between Two Dates You are given two calendar dates as strings in YYYY-MM-DD format. Return the number of days between them as a non-neg...
Maximum Group of Pairwise Strangers in an Acquaintance Tree
You are given a social network of n people, labeled 0 through n - 1. For some pairs of people, it is known that the two people in the pair know each o...
Compute maximum currency exchange rate
Compute maximum currency exchange rate You are given a set of currencies and the direct exchange rates between some pairs of them. Each direct exchang...
Implement placeholder-based pattern matcher
Implement placeholder-based pattern matcher You are given: 1. A string s that may contain placeholders delimited by the % character. 2. A dictionary d...