NIST

unranking

(algorithm)

Definition: Given a ranking, r, generate the rth permutation of n elements.

Note: This can be done in O(n) time.

Author: PEB

Implementation

(C). (Delphi?). Wendy Myrvold and Frank Ruskey, Ranking and Unranking Permutations in Linear Time, 13 April 2000, give linear time ranking and unranking algorithms.
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Entry modified 27 October 2022.
HTML page formatted Thu Oct 27 16:39:43 2022.

Cite this as:
Paul E. Black, "unranking", in Dictionary of Algorithms and Data Structures [online], Paul E. Black, ed. 27 October 2022. (accessed TODAY) Available from: https://www.nist.gov/dads/HTML/unrank.html