Identifier
- St001684: Permutations ⟶ ℤ
Values
[1] => 0
[1,2] => 0
[2,1] => 1
[1,2,3] => 0
[1,3,2] => 1
[2,1,3] => 1
[2,3,1] => 2
[3,1,2] => 2
[3,2,1] => 4
[1,2,3,4] => 0
[1,2,4,3] => 1
[1,3,2,4] => 1
[1,3,4,2] => 2
[1,4,2,3] => 2
[1,4,3,2] => 4
[2,1,3,4] => 1
[2,1,4,3] => 3
[2,3,1,4] => 2
[2,3,4,1] => 3
[2,4,1,3] => 4
[2,4,3,1] => 6
[3,1,2,4] => 2
[3,1,4,2] => 4
[3,2,1,4] => 4
[3,2,4,1] => 6
[3,4,1,2] => 5
[3,4,2,1] => 8
[4,1,2,3] => 3
[4,1,3,2] => 6
[4,2,1,3] => 6
[4,2,3,1] => 9
[4,3,1,2] => 8
[4,3,2,1] => 12
[1,2,3,4,5] => 0
[1,2,3,5,4] => 1
[1,2,4,3,5] => 1
[1,2,4,5,3] => 2
[1,2,5,3,4] => 2
[1,2,5,4,3] => 4
[1,3,2,4,5] => 1
[1,3,2,5,4] => 3
[1,3,4,2,5] => 2
[1,3,4,5,2] => 3
[1,3,5,2,4] => 4
[1,3,5,4,2] => 6
[1,4,2,3,5] => 2
[1,4,2,5,3] => 4
[1,4,3,2,5] => 4
[1,4,3,5,2] => 6
[1,4,5,2,3] => 5
[1,4,5,3,2] => 8
[1,5,2,3,4] => 3
[1,5,2,4,3] => 6
[1,5,3,2,4] => 6
[1,5,3,4,2] => 9
[1,5,4,2,3] => 8
[1,5,4,3,2] => 12
[2,1,3,4,5] => 1
[2,1,3,5,4] => 3
[2,1,4,3,5] => 3
[2,1,4,5,3] => 5
[2,1,5,3,4] => 5
[2,1,5,4,3] => 8
[2,3,1,4,5] => 2
[2,3,1,5,4] => 5
[2,3,4,1,5] => 3
[2,3,4,5,1] => 4
[2,3,5,1,4] => 6
[2,3,5,4,1] => 8
[2,4,1,3,5] => 4
[2,4,1,5,3] => 7
[2,4,3,1,5] => 6
[2,4,3,5,1] => 8
[2,4,5,1,3] => 8
[2,4,5,3,1] => 11
[2,5,1,3,4] => 6
[2,5,1,4,3] => 10
[2,5,3,1,4] => 9
[2,5,3,4,1] => 12
[2,5,4,1,3] => 12
[2,5,4,3,1] => 15
[3,1,2,4,5] => 2
[3,1,2,5,4] => 5
[3,1,4,2,5] => 4
[3,1,4,5,2] => 6
[3,1,5,2,4] => 7
[3,1,5,4,2] => 10
[3,2,1,4,5] => 4
[3,2,1,5,4] => 8
[3,2,4,1,5] => 6
[3,2,4,5,1] => 8
[3,2,5,1,4] => 10
[3,2,5,4,1] => 12
[3,4,1,2,5] => 5
[3,4,1,5,2] => 8
[3,4,2,1,5] => 8
[3,4,2,5,1] => 11
[3,4,5,1,2] => 9
[3,4,5,2,1] => 13
[3,5,1,2,4] => 8
[3,5,1,4,2] => 12
>>> Load all 141 entries. <<<
search for individual values
searching the database for the individual values of this statistic
/
search for generating function
searching the database for statistics with the same generating function
Description
The reduced word complexity of a permutation.
For a permutation $\pi$, this is the smallest length of a word in simple transpositions that contains all reduced expressions of $\pi$.
For example, the permutation $[3,2,1] = (12)(23)(12) = (23)(12)(23)$ and the reduced word complexity is $4$ since the smallest words containing those two reduced words as subwords are $(12),(23),(12),(23)$ and also $(23),(12),(23),(12)$.
This statistic appears in [1, Question 6.1].
For a permutation $\pi$, this is the smallest length of a word in simple transpositions that contains all reduced expressions of $\pi$.
For example, the permutation $[3,2,1] = (12)(23)(12) = (23)(12)(23)$ and the reduced word complexity is $4$ since the smallest words containing those two reduced words as subwords are $(12),(23),(12),(23)$ and also $(23),(12),(23),(12)$.
This statistic appears in [1, Question 6.1].
References
[1] Knutson, A., Miller, E. Subword complexes in Coxeter groups MathSciNet:2047852
Code
def statistic(pi):
ws = pi.reduced_words()
Ws = Words(sorted(ws[0]))
ws = [ Ws(w) for w in ws ]
n = pi.length()
while True:
for w in Ws.iterate_by_length(n):
if all(v.is_subword_of(w) for v in ws):
return n
n += 1
Created
Feb 20, 2021 at 14:50 by Christian Stump
Updated
Mar 06, 2023 at 18:20 by Nadia Lafreniere
searching the database
Sorry, this statistic was not found in the database
or
add this statistic to the database – it's very simple and we need your support!