Permutations with prescribed pattern
β Scribed by L. Carlitz
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- English
- Weight
- 576 KB
- Volume
- 58
- Category
- Article
- ISSN
- 0025-584X
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
We initiate a general approach for the fast enumeration of permutations with a prescribed number of occurrences of ''forbidden'' patterns that seems to indicate that the enumerating sequence is always P-recursive. We illustrate the method completely in terms of the patterns ''abc, '' ''cab,'' and ''
## Given a permutation T of 1 to n, and a permutation P of 1 to k, for k < n, we wish to find a k-element subsequence of T whose elements are ordered according to the permutation P. For example, if P is ( 1,2, . . . , k), then we wish to find an increasing subsequence of length k in T; this specia
GivenapermutationPof{l,..., k}andTof{l,..., n}, k < n, the pattern matching problem for permutations is to determine whether there is a length k subsequence of T whose elements are ordered in the same way as the elements of P. We present an 0( kn4) time and 0( kn3) space algorithm for finding a matc