Algorithms for Unranking Combinations and Other Related Choice Functions
نویسنده
چکیده
In this report new unranking algorithms are developed for a large class of choice functions representing various classes of combinatorial objects: combinations, complementary combinations, conjugative nondecreasing choice functions, ordered partitions. Presented algorithms differ with the type of lexicographical order they deal with and the method of binomial coefficient evaluation. The proofs of the correctness provide a unified insight into various existing unranking techniques. All obtained algorithms are the best known within their classes. New unranking algorithms can be applied in parallel systems for distribution subtasks among processors and for parallel generation of of choice functions including their ordered subsets and random sequences.
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