Algo Viewer vs Learn SQL

AlgoViewer helps you understand algorithms the way they were meant to be understood — by watching them work, step by step. Whether you're a CS student studying for exams, a developer preparing for technical interviews, or just someone curious about how sorting, searching, and graph traversal actually work, this app breaks it down visually so it clicks. WHAT'S INSIDE 40 algorithms and data structures across 6 categories: • Search — Linear, Binary, Interpolation, Jump, Exponential • Sorting — Bubble, Selection, Insertion, Merge, Quick, Heap, Shell, Counting, Radix • Linear Data Structures — Stack, Queue, Deque, Linked List, Doubly Linked List, Circular Linked List • Non-Linear Data Structures — Binary Tree, Binary Search Tree, AVL Tree, Heap, Hash Table • Graphs — BFS, DFS, Dijkstra, Prim, Kruskal, Bellman-Ford, Floyd-Warshall • Math — Factorial, Fibonacci, GCD, LCM, Sieve of Eratosthenes, Prime Factorization, Fast Exponentiation, Catalan Numbers • Home Screen and Lock Screen widgets: a new Algorithm of the Day every day, plus your streak and progress. HOW IT WORKS 1. Pick an algorithm 2. Enter your own data or use random values 3. Tap play and watch each step unfold with color-coded animations 4. Read the explanation to understand the "why" behind each step 5. Check out the code — every algorithm includes examples in Swift, Python, and Java BUILT FOR LEARNING • Step-by-step animations you can pause, step through, and speed up • Detailed explanations with complexity analysis and real-world use cases • Code examples in 3 languages with copy support • Time complexity charts so you can see how algorithms scale • Quizzes for every algorithm to test what you learned • Your progress, achievements, and favorites sync with iCloud • Light and dark mode • Available in English and Spanish FREE TO START, ONE-TIME UNLOCK 17 algorithms are free, forever. Unlock all 40 with a single one-time purchase: no subscriptions and no ads. Built with care by a developer who believes the best way to learn an algorithm is to see it in action.

Open the case file. The evidence is in the database. Learn SQL for free through 100 authored leads and 10 complete investigations. Read the brief, inspect the schema, write a real query, and use the returned rows to prove what happened. Each lead gives you a question and a working dataset. Run your SQL, study the result, revise your approach, then verify the finding when the evidence fits. Every investigation is authored, so the clues, datasets, and conclusions belong to a complete case. WORK 100 AUTHORED LEADS Ten investigations take you from the foundations to advanced analysis: • SELECT, WHERE, ORDER BY, and LIMIT • COUNT, SUM, AVG, GROUP BY, and HAVING • INNER JOIN and LEFT JOIN • Subqueries and CASE expressions • Window functions and common table expressions BUILD PRACTICAL SQL JUDGEMENT • Turn a case objective into a query • Explore tables and relationships through the schema • Read returned rows instead of guessing from syntax • Use clear feedback to correct a failed investigation • Reopen filed leads and improve your solution START WHERE YOUR SKILLS FIT New to SQL? Begin with Case 001 and learn the query desk step by step. Already comfortable with the basics? Choose a later investigation and meet a harder set of evidence. Archie, your SQL Case Guide, can offer a focused hint when you are stuck. Academy field guides explain the underlying concepts, while the Skill Map shows how each investigation builds your SQL toolkit. THE CURRICULUM STAYS FREE All 100 authored leads and the complete SQL learning route are free. There is no subscription. Start without an account, and keep your learning progress and settings on your device. Analytics can be disabled in Settings. Query verification, Archie guidance, verification links, and purchase restoration require an internet connection. An optional one-time Supporter purchase helps fund future investigations. It never limits the curriculum. Your first case is waiting.