formula for derangement - Search
Open links in new tab
  1. Derangement - Wikipedia

    • In combinatorial mathematics, a derangement is a permutation of the elements of a set in which no element appears in its original position. In other words, a derangement is a permutation that has no fixed points. The number of derangements of a set of size n is known as the subfactorial of n or the n th derangement number or n th de Montmort numb… See more

    Example

    Suppose that a professor gave a test to 4 students – A, B, C, and D – and wants to let them grade each other's tests. Of … See more

    Counting derangements

    Counting derangements of a set amounts to the hat-check problem, in which one considers the number of ways in which n hats (call them h1 through hn) can be returned to n people (P1 through Pn) such that no hat … See more

    Generalizations

    The problème des rencontres asks how many permutations of a size-n set have exactly k fixed points.
    Derangements are an example of the wider field of constrained permutations. For example, the … See more

    Computational complexity

    It is NP-complete to determine whether a given permutation group (described by a given set of permutations that generate it) contains any derangements.
    Table of factorial and derangement values Permutations, … See more

    Footnotes

    1. ^ The name "subfactorial" originates with William Allen Whitworth. See more

    External links

    Baez, John (2003). "Let's get deranged!" (PDF) – via math.ucr.edu.
    • Bogart, Kenneth P.; Doyle, Peter G. (1985). "Non-sexist solution of the ménage problem" – via math.dartmouth.edu.… See more

     
    Kizdar net | Kizdar net | Кыздар Нет
  1. Some results have been removed