INVARIANT
WATCH IT RUN · THEN RUN IT FROM MEMORY
20 DECKS · 2 LIVE · STEP 01 → 18

Watch it run.Then run it from memory.

Every algorithm animates one step at a time — then asks you to predict the next step before it shows you. Solve it, rate it, and it comes back on a spaced schedule.

0 1 2 3 4 5 6 7
BFS · FRONTIER — · STEP 00
01

Learn the Basics

Call-stack ladder
COMING SOON
02

Sorting Techniques

Bar-array animator
COMING SOON
03

Arrays

Array track + index cursors
COMING SOON
04

Binary Search

lo/mid/hi collapse
COMING SOON
05

Strings

Char track + frequency panel
COMING SOON
06

Linked List

Node boxes, re-routing arrows
COMING SOON
07

Recursion

Recursion tree + stack panel
COMING SOON
08

Bit Manipulation

32-cell bit strip
COMING SOON
09

Stacks & Queues

Monotonic-stack walk
COMING SOON
10

Sliding Window & Two Pointer

Dual pointers + window shade
COMING SOON
11

Heaps

Heap tree + array mirror
COMING SOON
12

Greedy Algorithms

Interval timeline
COMING SOON
13

Binary Trees

SVG tree + traversal numbering
COMING SOON
14

Binary Search Trees

Search path + restructure
COMING SOON
15

Graphs · Traversal

Graph canvas + state panel
BFS · DFS · cycle detection · bipartite · topological sort
26 PROBLEMS · OPEN →
15

Graphs · Shortest Paths

Graph canvas + state panel
Dijkstra · Bellman-Ford · Floyd-Warshall
13 PROBLEMS · OPEN →
15

Graphs · MST · DSU · SCC

Graph canvas + state panel
Prim · Kruskal · disjoint set · Kosaraju · Tarjan
COMING SOON
16

Dynamic Programming

4-step ladder + DP table filler
COMING SOON
17

Tries

Trie growth on insert
COMING SOON
18

Strings (Advanced)

KMP prefix-function builder
COMING SOON
←→ or AD · drag · scroll
■ REQUEST REFUSED
1280×720
FIXED STAGE · NOT RESPONSIVE BY DESIGN

Open this on a laptop

Every deck is a fixed 1280 × 720 stage — hand-built animated visualisers, code mirrored beside the graph, problems laid out two columns wide. It scales as one piece, so on this screen the body text would land at about 4px.

That is not worth shipping to you, so we are not going to pretend otherwise.

THIS SCREEN0 × 0
NEEDED≥ 1060 × 610
WHAT IS WAITING FOR YOU
INVARIANT · WATCH IT RUN · THEN RUN IT FROM MEMORY