AlgoLearn
LEARN / ALGORITHM PATTERNS
Twenty topics that explain why solutions look the way they do.
Learn the pattern once, then recognise it across dozens of problems.
01// watch every algorithm run
Step through the code one line at a time.
This is problem #1, Two Sum, the way the app shows it: the array, the hash map filling up, and the exact line being executed. Change the target or the language and run it again.
nums
seen (value → index)
02// understand before you memorize
Every problem is taught, not just listed.
Problem
A plain statement in the app's own words, with level and pattern tags.
Example
Input, output and the explanation that connects them.
Intuition
The idea in a paragraph, before any code: “for each number, the partner you need is target − num.”
Algorithm
Language-neutral pseudocode you can hold in your head.
Visualize
Play, pause and scrub through the run, with every variable on screen.
Implementation & complexity
Swift, Python, Java, C++, C and JavaScript, with time and space analysis.
Practice
Write and run JavaScript against test cases, then keep your notes with the problem.
03// patterns, system design, and the interview itself
The whole loop, not only the coding round.
Sixteen lessons, five guided labs.
Design on a canvas, then check your reasoning.
- Global URL Redirects
- Personalized Activity Feed
- Webhook Delivery Platform
- Global Checkout Platform
- Media Processing Pipeline
Built for your role.
Software Engineer102
Mobile Engineer100
Data Engineer83
Backend Engineer42
Recommended problems of 137, most valuable first.
Practice under real pressure.
A countdown, a scratchpad and a hidden solution. Reveal and compare when you're done, then keep the scorecard.
Ask about this problem.
Explain the intuition more simplyWalk me through a small exampleWhy is the time complexity that?
Answers run privately on your device and won't always be perfect.
04// everything else in the box
Three levels. One habit.
Most interviews live in the middle, so most of the problems do too.
39 easy
77 medium
21 hard
review/Spaced reviewKeeps solved problems from fading.daily/Daily challengeOne problem a day, and a weekly sprint.flashcards/Flashcard drillsQuick-fire recall, with a scorecard at the end.mistakes/Mistake notebookCapture what went wrong while it's fresh.recursion/Recursion visualizerWatch the call tree grow and unwind.graphs/Graph playgroundDraw a graph, run a traversal on it.race/Algo raceTwo algorithms, same input, side by side.big-o/Complexity calculatorAnd a one-page cheat sheet.templates/Code templatesThe skeletons worth knowing by heart.behavioral/STAR story editorPrepare the non-coding answers too.readiness/Readiness checkAn honest read on where you stand.stats/Heatmap & goalsStudy streaks you can actually see.05// on the big screen
Six languages, side by side.
On iPad the problem, the visualizer and the implementation share one screen. Switch language with a tap and the solution follows.
SwiftPythonJavaC++CJavaScript
06// pricing.json
Try it properly before you pay.
Free
$0
- 5 Level 1 problems, in full
- 3 theory lessons
- System design introduction
- The first guided design lab
AlgoLearn Pro
$29.99 / year · or $4.99 / month
- All 137 problems and every visualizer
- All 20 patterns, 16 lessons, 5 labs
- Role study paths and mock interviews
- Review, drills and the full toolkit
// USD; prices may vary by region. Auto-renews until cancelled. Cancel anytime in Settings.
