Возможность и сложность распознавания графов тремя агентами

Problem of exploration finite graphs by three agents is considered. Constructed an algorithm for exploration undirected graphs with $O (n^2)$ (n is amount of nodes of graph) time and space complexities. Two agents (which move on graph) needs two different colors (in total three colors) for graph exploration. An algorithm is based on depth-first traversal method.