The Power of Team Exploration: Two Robots Can Learn Unlabeled Directed Graphs

Abstract

We show that two cooperating robots can learn exactly any strongly-connected directed graph with n indistinguishable nodes in expected time polynomial in n. We introduce a new type of homing sequence for robots, which helps the robots recognize certain previously-seen nodes. We represent an algorithm in which the robots learn the graph and the homing sequence simultaneously by actively wandering through the graph.