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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"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 max word letter span
Implement a function that, given an input text string, computes the maximum word letter span and returns both (a) the maximum span and (b) the list of...
Find next and closest palindromes
Given a non-negative integer represented as a string n (no leading zeros unless n == "0"), return the smallest palindromic integer strictly greater th...
Find shortest path and compare BFS vs DFS
Given an unweighted graph (directed or undirected), explain how to find the shortest path between two nodes without writing code. Describe the algorit...
Compute minimum required meeting rooms
Given a list of meeting time intervals [start, end) for many events, determine the minimum number of rooms required so no meetings overlap in the same...
Solve grid shortest path with BFS
Given a 2D grid containing 0s (open cells) and 1s (walls), and coordinates for a start (sr, sc) and a target (tr, tc), return the length of the shorte...
Implement binary tree in-order traversal
Given the root of a binary tree, return the in-order ordering of its node values. Implement both a recursive solution and an iterative solution using ...
Determine and print expression to reach target
You are given four numbers and a target T (e.g., 24). Using +, −, ×, ÷ and parentheses, and using each number exactly once, determine whether you can ...
Find earliest common meeting slot
Given K participants' calendars, each a list of busy intervals [start, end) within a working window [workStart, workEnd], and a meeting duration d min...
Implement file deduplication at scale
Write a program to deduplicate files in a very large directory tree. Identify groups of identical files without loading entire files into memory. Outl...
Debug using logs and allocate tasks
You inherit a service where unit tests pass locally, but production logs show intermittent errors. Without a debugger, outline a step-by-step debuggin...
Design dynamic connectivity with alive nodes
Design a data structure to maintain an undirected graph of N nodes, where each node has a boolean 'alive' flag. Support the following operations effic...
Implement and analyze number-pattern function
Implement a function print_number_lines(n) that prints n lines, where the i-th line contains the integers from 1 to i separated by spaces (e.g., n=3 p...
Find minimum time for irrecoverable password
A password is a string s of length n. A virus attacks positions in a 1-indexed order given by a permutation attackOrder[1..n]. At second t (1 <= t <= ...
Maximize credits with limited skips
You are given n warehouses with inventories inventory[0..n-1], and two dispatch amounts: you dispatch dispatch1 units first each turn, then your co-wo...
Implement and compare round-robin and consistent hashing
Implement a round-robin load balancer that selects among service nodes, skipping unavailable nodes and wrapping around correctly. Fix typical pitfalls...
Design mutable sum-tree with fast queries
You're given a rooted, mutable tree. Each leaf node stores an integer value. Each internal node's value equals the sum of its immediate children's val...
Find leftmost point of maximum brightness
You are given an array of lights, where each light is [p, r] representing a lamp centered at coordinate p on the real number line with radius r, illum...
Design and implement a Python solution
Design and implement a solution in Python for a problem specified by the interviewer. Outline your approach and chosen data structures, justify key de...
Compute min operations to transform integers
Given integers A and B, transform A into B using the minimum number of operations. Allowed operations: ( 1) subtract 1 from the current value; ( 2) mu...
Compute maximum simultaneous bus routes
You are given N bus routes, each defined by a start time (inclusive) and an end time (exclusive). Compute the maximum number of routes running simulta...