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."
Solve a Skyscraper puzzle efficiently
Design and implement a solver for the Skyscraper logic puzzle on an $N \times N$ grid, where $3 \le N \le 7$. The board is a grid of building heights....
Cross-reference logs to flag spam numbers
You are given two data sets: ( 1) a call log containing phone numbers observed in calls and ( 2) a list of user reports where each entry is a phone nu...
Find word sequence with 1–2 char changes
Given a beginWord, an endWord, and a dictionary (wordList) of unique same-length lowercase words, determine whether there exists a transformation sequ...
Convert BST to sorted doubly list
Convert a binary search tree into a sorted doubly linked list in-place. Reuse the existing tree nodes: the left pointer becomes prev and the right poi...
Compute height after deletions; enumerate valid delete sets
Warm-up: You are given a rooted binary tree with unique node ids and a list of ids to delete. When a node is deleted, promote all of its children to b...
Filter hierarchical paths after deletions
Given two arrays: ( 1) paths — slash-delimited hierarchical strings such as "California", "California/San Francisco", "California/San Francisco/7th St...
Design O(1) random-sampling set
Design a data structure that supports insert(x), remove(x), and get_random() that returns a uniformly random element among the present items, all in e...
Check near-palindrome with one deletion
Given a string s, determine if it can become a palindrome after deleting at most one character. Return true or false and provide time and space comple...
Design Manhattan-distance meeting point finder
Given an m×n grid with cells marked 1 for homes and 0 otherwise, choose a single meeting cell that minimizes the sum of Manhattan distances from all h...
Sort by squares and find k-th smallest
Given a nondecreasing sorted array of integers nums, do the following: 1) Reorder the original elements by increasing square value (equivalently, by a...
Solve BST range average and merge intervals
1) Given a binary search tree and an inclusive range [L, R], compute both the sum and the average of all node values where L <= val <= R. Use the BST ...
Compute longest distinct substring, case-insensitive
Given a string s, return the length of the longest contiguous substring that contains no repeated characters, treating letters case-insensitively (e.g...
Simulate stack traces from logs
Given a list of log entries describing function calls, each formatted as "<id> <event> <timestamp>" where event ∈ {START, END} and timestamps are inte...
Implement a recency-eviction bounded cache
Implement an in-memory key–value store with a fixed capacity N that uses recency-based eviction. Support: get(key) -> value or -1 if missing, and put(...
Sort and merge string lists by length
Given two unsorted lists of strings, return a single list sorted by ascending string length. Specify your tie-breaking rule for equal-length strings (...
Design a parser for a hypothetical language
You are given a set of syntax rules for a hypothetical programming language written in BNF/EBNF. Design data structures and algorithms that: ( 1) pars...
Validate palindrome with constraints
Given a string s, return true if s reads the same forward and backward after removing all non-alphanumeric characters and ignoring letter case. Implem...
Optimize 0/1 to bounded knapsack DP
Solve the 0/1 knapsack problem: given arrays weight[i], value[i] for i=0..n-1 and capacity W, return the maximum value and reconstruct one optimal set...
Solve tree partition and IPO allocation
1) Tree partitioning for minimum difference: Given a rooted tree as an array parent of length n (parent[i] gives the parent of node i, and parent[root...
Compute maximum simultaneous drivers
Given N driver online intervals [start_time, end_time) during a day, compute the maximum number of drivers simultaneously online at any moment. Handle...