Election and traversal in unidirectional networks

This paper presents distributed algorithms for election and traversal in strongly connected unidirectional networks. A unidirectional network consists of nodes which are processors connected by unidirectional communication links. Initially, processors differ by their identifier but are otherwise similar. The election algorithm distinguishes a single processor from all other processors. The election algorithm requires <italic>O</italic>(log <italic>n</italic>) bits of memory in each processor and has communication complexity of <italic>O</italic>(<italic>n</italic> • <italic>m</italic>+<italic>n</italic><supscrpt>2</supscrpt>log <italic>n</italic>) bits. In the traversal algorithm one node initiates a token which visits all the nodes of the network and returns to the initiator. The traversal algorithm is derived from the election algorithm. It achieves the same communication complexity and uses only <italic>O</italic>(1) bits of memory in each processor.