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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Decode an Encrypted Paragraph Tree
Decode an Encrypted Paragraph Tree A document is stored as a tree of paragraphs. Each node holds a paragraph text — a string of lowercase English lett...
Maximum Currency Conversion Rate
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Solve Banana Speed and Interval Merge
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Implement IPv4 and CIDR iterators
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Solve classic array, graph, and parsing problems
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Solve the following coding tasks: 1) Maximum Points from Different Categories: Given an array of items (category, points) and an integer k, choose exa...
Find largest digit-sum bucket size
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Implement bag-of-words similarity search from scratch
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Solve tree traversal and interval merging tasks
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Solve k-Nearest Places by Latitude/Longitude
Given a set of geographic coordinates and a query point, return the k nearest locations. Describe how you compute great-circle distance (e.g., Haversi...
Solve permutation successor and evaluate expressions
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Compute maximum sum in a tree without adjacency
Given a tree where each node has an integer value, select a subset of nodes to maximize the sum under the constraint that if you choose a node, you ca...
Implement in-place duplicate removal
Given a non-decreasing array of integers, overwrite it in-place so that each distinct value appears exactly once while preserving the order of the uni...
Remove runs of length at least k
Given a string s and an integer k (k >= 2), repeatedly remove every maximal contiguous group of the same character whose length is at least k, deletin...
Maximize tokens from nested crates
You are given n crates, each either locked or unlocked. Each crate i contains: an integer tokens[i]; a list of keys that can unlock other crates; and ...
Implement text formatter and sum subarray products
1) Text formatter (LC-inspired variant): Given an array of words and an integer maxWidth W >= 1, break the words into lines so that the total length o...
Compute maximum beauty of a string
Given a string s, define the beauty of each letter a–z as a distinct integer between 1 and 26, case-insensitive. The beauty of a string is the sum ove...