Cache-Oblivious Comparison-Based Algorithms on Multisets

Abstract. We study three comparison-based problems related to multisets in the cache-oblivious model: Duplicate elimination, multisorting and finding the most frequent element (the mode). We are interested in minimizing the cache complexity (or number of cache misses) of algorithms for these problems in the context under which cache size and block size are unknown. We give algorithms with cache complexities that are within a constant factor of the optimal for all the first two problems. For the mode, The deterministic algorithm differs from the lower bound by a sublogarithmic factor. We can achieve optimality either with a randomized method or if given lg lg(relative frequency of the mode) with a constant additive error.

• Type: Conference
• Year: 2005
• Where: ESA
• Authors: Arash Farzan, Paolo Ferragina, Gianni Franceschini, J. Ian Munro
• Keywords: Cache, Cache Complexity, Cache Misses, ESA 2005