The graph scan algorithm traverses all reachable nodes in a graph. Its behaviour can be changed by plugging in different datastructures: Using an unordered set results in a random search, using a stack yields depth-first search, and using a queue gives breadth-first search.

• v1.0: Initial version
• v1.1: Fix a mistake in the bottom BROAD SEARCH example
• v1.2: Change title from GRÅPH SCÄN to GRÅPH SKÄN to make it sound even more Swedish
• v1.3: Update the IDEA logo

Initially published 2017-11-29.

IDEA is a series of nonverbal algorithm assembly instructions, developed by Sándor P. Fekete and blinry. The instructions explain how various popular algorithms work, entirely without text. This also allows the instructions to be understood interculturally.

All instructions are available under Creative Commons licenses, so everyone is free to share and adapt them in noncommercial settings. We hope they will be useful in all sorts of contexts, for teachers, students, and curious people alike. Visit the about page to learn more, or download all instructions as a PDF.