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."
Minimize cost & recommend movies
Question Given arrays size[] and cost[] where size[i] is the size of the i-th product and cost[i] is the cost to increase size[i] by one unit, compute...
Solve three LeetCode coding problems
Question LeetCode 1249. Minimum Remove to Make Valid Parentheses LeetCode 827. Making A Large Island LeetCode 199. Binary Tree Right Side View https:/...
Find integer in most intervals
Question Given N integer intervals [ai, bi] (positive integers), find an integer that belongs to the maximum number of intervals (return any such inte...
Randomly partition array into k segments
Question Given a list of integers and an integer k representing the number of segments, write a function that randomly partitions the list into k non-...
Solve island connectivity and string multiplication
Question Given N distinct islands (e.g., a, b, c…) and a list of existing undirected paths between them, compute the minimum number of additional path...
Count islands and distinct shapes
Question LeetCode 200. Number of Islands LeetCode 694. Number of Distinct Islands https://leetcode.com/problems/number-of-islands/description/ https:/...
Solve island and frequency problems
Question LeetCode 200. Number of Islands – given a 2D grid, count the number of connected islands of '1's using DFS/BFS/Union-Find. LeetCode 695. Max ...
Handle multi-source string matching and tagging
Question Given an LLM output string and a list of source strings, design an algorithm to count how many times each source appears in the output. Exten...
Implement in-memory DB querying
Question Implement an in-memory database that supports: 1. Querying the whole table and returning only selected columns (projection). 2. Adding WHERE ...
Implement thread-safe blocking queue
Question Design and implement a thread-safe bounded blocking queue that supports concurrent enqueue and dequeue operations using standard synchronizat...
Compute minimum passes over permutation
Question You are given an array shelf representing a permutation of the integers 1..n. Starting with target = 1, you repeatedly scan the array left-to...
Solve diverse LeetCode algorithm problems
Question LeetCode 695. Max Area of Island LeetCode 380. Insert Delete GetRandom O( 1) LeetCode 19. Remove Nth Node From End of List LeetCode 1004. Max...
Round numeric string values
Question Given a numeric string, implement rounding to the nearest integer (e.g., '3.5' → '4', '100.01' → '100'). Follow-up: round to the last signifi...
Find shortest path with blocked nodes
Question Given an unweighted graph, a start node, an end node, and a block_set of nodes that cannot be traversed, return the length of the shortest pa...
Solve intervals and distinct islands
Question LeetCode 56. Merge Intervals LeetCode 694. Number of Distinct Islands https://leetcode.com/problems/merge-intervals/description/ https://leet...
Parse password from indexed matrix file
Question Given a filepath to a text file containing one index line [x, y] followed by a matrix of characters (origin at lower-left (0, 0)), return the...
Reconstruct tree from inorder and postorder
Given two arrays representing the inorder and postorder traversals of a binary tree with unique values, reconstruct the original binary tree and retur...
Find index of first unique character
Find index of first unique character Given a string s, return the index of the first character that appears exactly once; if none exists, return -1. A...
Implement two-pointer unique-pair sum search
Implement two-pointer unique-pair sum search Given a nondecreasing integer array nums and an integer target, return all unique value pairs [a, b] with...
Find missing number from concatenated digits
Given an integer n (1 ≤ n ≤ 99) and a digit string s formed by concatenating the decimal representations of the integers 1..n except for one missing n...