enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Lehmer code - Wikipedia

    en.wikipedia.org/wiki/Lehmer_code

    The usual way to prove that there are n! different permutations of n objects is to observe that the first object can be chosen in n different ways, the next object in n − 1 different ways (because choosing the same number as the first is forbidden), the next in n − 2 different ways (because there are now 2 forbidden values), and so forth.

  3. Superpermutation - Wikipedia

    en.wikipedia.org/wiki/Superpermutation

    Finally, each resulting structure is placed next to each other and all adjacent identical symbols are merged. [2] For example, a superpermutation of order 3 can be created from one with 2 symbols; starting with the superpermutation 121 and splitting it up into the permutations 12 and 21, the permutations are copied and placed as 12312 and 21321.

  4. Cycles and fixed points - Wikipedia

    en.wikipedia.org/wiki/Cycles_and_fixed_points

    (2.c) Finally: s(k, 1) = k!/k = (k − 1)!. (3) There are two different ways to construct a permutation of k elements with j cycles: (3.a) If we want element k to be a fixed point we may choose one of the s(k − 1, j − 1) permutations with k − 1 elements and j − 1 cycles and add element k as a new cycle of length 1.

  5. Permutation pattern - Wikipedia

    en.wikipedia.org/wiki/Permutation_pattern

    In combinatorial mathematics and theoretical computer science, a (classical) permutation pattern is a sub-permutation of a longer permutation.Any permutation may be written in one-line notation as a sequence of entries representing the result of applying the permutation to the sequence 123...; for instance the sequence 213 represents the permutation on three elements that swaps elements 1 and 2.

  6. Cyclic permutation - Wikipedia

    en.wikipedia.org/wiki/Cyclic_permutation

    A cyclic permutation consisting of a single 8-cycle. There is not widespread consensus about the precise definition of a cyclic permutation. Some authors define a permutation σ of a set X to be cyclic if "successive application would take each object of the permuted set successively through the positions of all the other objects", [1] or, equivalently, if its representation in cycle notation ...

  7. Heap's algorithm - Wikipedia

    en.wikipedia.org/wiki/Heap's_algorithm

    A map of the 24 permutations and the 23 swaps used in Heap's algorithm permuting the four letters A (amber), B (blue), C (cyan) and D (dark red) Wheel diagram of all permutations of length = generated by Heap's algorithm, where each permutation is color-coded (1=blue, 2=green, 3=yellow, 4=red).

  8. Permutation codes - Wikipedia

    en.wikipedia.org/wiki/Permutation_Codes

    A main problem in permutation codes is to determine the value of (,), where (,) is defined to be the maximum number of codewords in a permutation code of length and minimum distance . There has been little progress made for 4 ≤ d ≤ n − 1 {\displaystyle 4\leq d\leq n-1} , except for small lengths.

  9. In-place matrix transposition - Wikipedia

    en.wikipedia.org/wiki/In-place_matrix_transposition

    That is, they loop over the cycles, moving the data from one location to the next in the cycle. In pseudocode form: for each length>1 cycle C of the permutation pick a starting address s in C let D = data at s let x = predecessor of s in the cycle while x ≠ s move data from x to successor of x let x = predecessor of x move data from D to ...