combinatorial-0.1: Count, enumerate, rank and unrank combinatorial objects

Combinatorics.Permutation.WithoutSomeFixpoints

Synopsis

enumerate :: Eq a => Int -> [a] -> [[a]] Source #

enumerate n xs list all permutations of xs where the first n elements do not keep their position (i.e. are no fixpoints).

enumerate n xs

xs

n

This is a generalization of derangement.

Naive but comprehensible implementation.

numbers :: Num a => [[a]] Source #

http://oeis.org/A047920