Reputation
1,306
Top tag
Next privilege 2,000 Rep.
Edit questions and answers
Badges
5 10
Newest
 Yearling
Impact
~10k people reached

  • 0 posts edited
  • 2 helpful flags
  • 166 votes cast
Jan
25
comment A rather special monoid
@Lehs Is the obvious way to compose subsets as follows: Given $S, T \subseteq \mathcal{P}(S_n)$, $ST = \{u | \exists s\in S, t\in T, st = u\}$? So, if $S = \{x\}$ and $T = \{x^{-1}\}$, does $ST = \{e\}$?
Nov
17
comment Zero-One Optimization
I am aware of some heuristic approaches to the basic PARTITION problem but those may or may not be applicable to your situation. For example, if $n$ (the number of $A_i$) is large, then I suspect that your problem's characteristics diverge significantly from PARTITION. The effectiveness of heuristic approaches may be dependent on the precise parameters of your problem instances (e.g.: the number of $A_i$, the range of $c$, etc...).
Nov
17
answered Zero-One Optimization
Oct
20
comment How many ways are there to pile $n$ “$1\times 2$ rectangles” under some conditions?
I found the connection to "directed animals" by checking OEIS for each of the columns in the first table.
Oct
20
awarded  Yearling
Oct
20
revised How many ways are there to pile $n$ “$1\times 2$ rectangles” under some conditions?
Added statement of corollary; minor wording change
Oct
19
revised How many ways are there to pile $n$ “$1\times 2$ rectangles” under some conditions?
Fixed definition of "directed animal"
Oct
19
answered How many ways are there to pile $n$ “$1\times 2$ rectangles” under some conditions?
Aug
5
answered Vertex Reconstruction Conjecture For Asymmetric Graphs
Jul
24
awarded  Organizer
Jul
24
revised Prove it by theory of combination
removed algebraic-geometry tag
Jul
24
suggested approved edit on Prove it by theory of combination
Jun
4
comment The $5n+1$ Problem
It's not clear from the excerpt I quoted, but in that article the "size" of a cycle refers to the number of distinct odd elements in the cycle, not the length.
Apr
22
answered On the invertibility of adjacency matrix
Feb
25
awarded  Yearling
Feb
25
answered Hash functions for unordered data
Feb
23
comment Hash functions for unordered data
You may want to look into count-min sketches (essentially, the multi-set version of Bloom filters).
Feb
18
answered When a set of consecutive numbers can be covered by differences between distinct integers?
Dec
19
awarded  Caucus
Nov
10
answered Open mathematical questions for which we really, really have no idea what the answer is