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."
Determine minimal substitutions and removals
Question Given a list of words, determine the minimum number of character substitutions required so that, in every word, no two adjacent characters ar...
Solve LeetCode array & stream problems
Question LeetCode 346. Moving Average from Data Stream LeetCode 249. Group Shifted Strings LeetCode 163. Missing Ranges Remove duplicates from a chara...
Determine Rounds for Star Substring Threshold
Question Given a string S, an offset array O (replacement order), and an integer M, repeatedly replace S[O[i]] with ''. Determine the minimum number o...
Solve classic LeetCode problems
Question LeetCode 215. Kth Largest Element in an Array LeetCode 249. Group Shifted Strings Variant of LeetCode 56. Merge Intervals extended to 2-D rec...
Solve diameter and shortest bridge problems
Question LeetCode 543. Diameter of Binary Tree LeetCode 934. Shortest Bridge https://leetcode.com/problems/diameter-of-binary-tree/description/ https:...
Solve 4 LeetCode algorithm problems
Question LeetCode 636. Exclusive Time of Functions LeetCode 253. Meeting Rooms II LeetCode 314. Binary Tree Vertical Order Traversal LeetCode 215. Kth...
Compute concurrent online drivers
Question Given each driver’s chronologically sorted delivery records, build an algorithm that, for a timestamp t, returns how many distinct drivers we...
Check tree nodes equal subtree average
Question LeetCode 2265. Count Nodes Equal to Average of Subtree – Adapted: Verify that every node’s value equals the average of all values in its subt...
Find Top K Frequent Elements
Question LeetCode 347. Top K Frequent Elements – given an integer array nums, return the k most frequent elements. Initial requirement: return the top...
Find lowest common ancestor
Question LeetCode 236. Lowest Common Ancestor of a Binary Tree — Given a binary tree, find the lowest common ancestor (LCA) of two given nodes. Follow...
Reverse a linked list
Question LeetCode 206. Reverse Linked List — Given the head of a singly linked list, reverse the list and return the reversed list. https://leetcode.c...
Compare two string linked lists
Question Given two singly linked lists where each node stores one character as a string, determine whether the sequences of characters represented by ...
Convert bitmap into ASCII characters
Question Given an array/string of 0-1 bits representing a bitmap font, write code to render each character as a grid using '.' for 0 and '#' for 1, an...
Find largest island area
Question Given a 2D grid of 0s and 1s, find the largest area of a connected group of 1s (island) using 4-directional adjacency; return that area. (Var...
Count changed nodes in N-ary trees
Question Given two N-ary trees (old and new versions) where each node has a key (string), value (int), and list of children, compute how many nodes ar...
Solve various LeetCode data-structure questions
Question LeetCode 129. Sum Root to Leaf Numbers LeetCode 2089. Find Target Indices After Sorting Array LeetCode 270. Closest Binary Search Tree Value ...
Design prefix-sum function and max stack
Question LeetCode 303. Range Sum Query – Immutable (design a reusable prefix-sum function) LeetCode 716. Max Stack (similar design question) https://l...
Find closest BST value and remove parentheses
Question LeetCode 270. Closest Binary Search Tree Value LeetCode 1249. Minimum Remove to Make Valid Parentheses (follow-up: achieve without using a st...
Solve tree leaf sum and target indices search
Question LeetCode 129. Sum Root to Leaf Numbers LeetCode 2089. Find Target Indices After Sorting Array (array already sorted; require O(log n) time) h...
Calculate area, flush probability, egg drops
Question Given two quarter-circles inside a 1×1 square (centers at bottom-left and top-right corners), find the exact area of their overlapping region...