AlgoFlex

AlgoFlex is a smarter way to prep for coding interviews. Instead of staring at a blank editor, you work through each algorithm problem as a series of quick multiple-choice steps — so you actually learn how to think your way to a solution. Every problem walks you through four stages: recognize the pattern, design the approach, choose the right variables, and assemble the implementation. With over 3,500 problems across the data structures and algorithms that interviewers love, you can practice anywhere — on the train, in line, between meetings — without a laptop. From "Two Sum" to dynamic programming and graphs, AlgoFlex covers the full spectrum at easy, medium, and hard difficulty, with explanations on every option so each question teaches you something. Features: - 3,500+ algorithm problems across 10 categories: Arrays, Strings, Linked Lists, Trees, Graphs, Dynamic Programming, Sorting & Searching, Math & Logic, Backtracking & Recursion, Stack & Queue - A 4-stage method that builds problem-solving intuition: pattern recognition → algorithm design → variable selection → code implementation - Multiple-choice format you can practice one-handed, anywhere — no keyboard needed - Explanations for every answer choice, right or wrong - Easy, medium, and hard difficulty - Progress tracking and completion celebrations per category - Beautiful developer color themes (Dracula, Nord, Monokai, Solarized, One Dark and more) with syntax-highlighted previews - Mark favorites to revisit - 100% offline — no account required