データ楽

This educational and visualization app helps you understand data structures not by "reading" them, but by "seeing and understanding them in action."

Abstract concepts such as stacks, queues, trees, and hash tables can be experienced through animations where the structure itself transforms in response to user interaction.

【Included Data Structures】
■ Basic (4 types)
・Stack (LIFO) — Experience Last-In, First-Out through loading and unloading movements
・Queue (FIFO) — Movement of a matrix with separate entry and exit points
・Array — Visualize random access and shifts during insertion and deletion
・Linked List — Connect nodes with arrows and rearrange them through insertion and deletion

■ Advanced (4 types)
・Tree (Binary Search Tree) — Distribute elements to the left or right based on size comparison and drop them to their designated positions
・Heap — Up-and-down movement (up-heap / down-heap) in a complete binary tree
・Hash Table — Keys instantly jump to their storage location via a hash function
・Graph — Visualize adjacency relationships using nodes and edges

【Features】
・Intuitively understand "what's happening now" with colors and movements
・Confirm the meaning of each operation with operation logs
・Explanations included for each structure — Computational complexity (access/search/insert/delete), advantages and disadvantages, and real-world applications
* No ads during animation playback, designed to maintain immersion
* Smartphone/tablet compatible
* Supports both Japanese and English (follows device language settings)

【Recommended for】
* Students and beginners learning programming
* Those preparing for exams such as the Fundamental Information Technology Engineer exam
* Engineers who want to re-understand data structures visually
* Intellectually curious individuals who enjoy seeing things in motion

【Connection to the Raku Series】
The second installment in the Raku series of information-related apps. It is mutually linked with the first installment, "Algorithm Visualization (Algorithm Visualization)," allowing you to jump from DataRaku's heap screen to AlRaku's heap sort screen, and from DataRaku's graph screen to AlRaku's BFS/DFS screen. You can learn both "how the process works" and "the foundation/structure on which that process operates."

【About Usage】
This app is completely free. There are no in-app purchases or subscriptions. We display ads (banner and full-screen ads) via Google AdMob to maintain and improve the app, but we have designed it so that no ads are displayed while animations are playing.