The complexity of searching a graph
Journal of the ACM (JACM)
Robust algorithms for packet routing in a mesh
SPAA '89 Proceedings of the first annual ACM symposium on Parallel algorithms and architectures
Computing with unreliable information
STOC '90 Proceedings of the twenty-second annual ACM symposium on Theory of computing
Monotonicity in graph searching
Journal of Algorithms
Theoretical Computer Science
Information and Computation
Lower bounds for noisy Boolean decision trees
STOC '96 Proceedings of the twenty-eighth annual ACM symposium on Theory of computing
Self-stabilizing end-to-end communication
Journal of High Speed Networks
Exploring unknown environments
STOC '97 Proceedings of the twenty-ninth annual ACM symposium on Theory of computing
Computation in noisy radio networks
Proceedings of the ninth annual ACM-SIAM symposium on Discrete algorithms
Exploring unknown undirected graphs
Proceedings of the ninth annual ACM-SIAM symposium on Discrete algorithms
Bubbles: Adaptive Routing Scheme for High-Speed Dynamic Networks
SIAM Journal on Computing
Routing on butterfly networks with random faults
FOCS '95 Proceedings of the 36th Annual Symposium on Foundations of Computer Science
SFCS '85 Proceedings of the 26th Annual Symposium on Foundations of Computer Science
Upper and lower bounds for routing schemes in dynamic networks
SFCS '89 Proceedings of the 30th Annual Symposium on Foundations of Computer Science
Expanders might be practical: fast algorithms for routing around faults on multibutterflies
SFCS '89 Proceedings of the 30th Annual Symposium on Foundations of Computer Science
SFCS '90 Proceedings of the 31st Annual Symposium on Foundations of Computer Science
Searching games with errors---fifty years of coping with liars
Theoretical Computer Science
Mobile Search for a Black Hole in an Anonymous Ring
DISC '01 Proceedings of the 15th International Conference on Distributed Computing
Mobile agent-based search for service discovery on dynamic peer-to-peer networks
AAAI'04 Proceedings of the 19th national conference on Artifical intelligence
Service discovery on dynamic peer-to-peer networks using mobile agents
AP2PC'04 Proceedings of the Third international conference on Agents and Peer-to-Peer Computing
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We consider the problem of searching for a piece of information in a fully interconnected computer network (or clique) by exploiting advice about its location from the network nodes. Each node contains a database that "knows" what kind of documents or information are stored in other nodes (e.g. a node could be a Web server that answers queries about documents stored on the Web). The databases in each node, when queried, provide a pointer that leads to the node that contains the information. However, this information is up-to-date (or correct) with some bounded probability. While, in principle, one may always locate the information by simply visiting the network nodes in some prescribed ordering, this requires a time complexity in the order of the number of nodes of the network. In this paper, we provide algorithms for locating an information node in the complete communication network, that take advantage of advice given from network nodes. The nodes may either give correct advice, by pointing directly to the information node, or give wrong advice by pointing elsewhere. We show that, on the average, if the probability p that a node provides correct advice is asymptotically larger than 1/n, where n is the number of the computer nodes, then the average time complexity for locating the information node is, asymptotically, 1/p or 2/p depending on the available memory. The probability p may, in general, be a function of the number of network nodes n. On the lower bounds side, we prove that no fixed memory deterministic algorithm can locate the information node in finite expected number of steps. We also prove a lower bound of 1/p for the expected number of steps of any algorithm that locates the information node in the complete network.