Questions tagged [multiset]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
0answers
126 views

An equation involving multisets

For finite multisets $A, B, C, A', B', C'$, if $A \uplus B \uplus \{B \uplus C\} \uplus \{A \uplus \{C\}\}$ = $A' \uplus B' \uplus \{B' \uplus C'\} \uplus \{A' \uplus \{C'\}\}$, must $A=A',B=B',C=C'$, ...
2
votes
1answer
205 views

The category of Multisets and Spans: morphism composition and tensor product

I have been thinking about multisets for a while. These are sets where elements can repeat, so $S =\{ a,a,b,c,b\}$ is a multiset on the set $A = \{a,b,c\}$. I have also been looking into morphisms ...
1
vote
1answer
237 views

The combinations of a finite multiset [closed]

Suppose there is a basket $S$ containing $3\ \color{blue}{blue}$, $2\ \color{green}{green}$ and $1\ \color{red}{red}$ balls. A subject can extract any $k$ number of balls (including $0$) at random ...
3
votes
2answers
344 views

Counting Specific Permutations of Elements in a Multiset

I have a question regarding counting permutations of a multiset's elements. The problem is the following: Given a multi-set $M=\{0^{m}, 1^{n-m}\}$ the number of all possible permutations of its ...
1
vote
1answer
538 views

What is the fastest way to sort numbers lexicographically?

I have $N$ sequences of numbers. None of them is longer than $10^6$. I want to sort those sequences lexicographically. For example, given sequences {1, 2, 4}, {1, 2, 3}, {2, 5, 7}, {2}, I want to have ...
1
vote
0answers
189 views

A natural sum over multisets (expectation over multinomial)

I think this is a natural question but am not sure where to find resources. Consider the possible multisets arising from choosing $n$ times an item from one of $k$ categories. We can represent one ...
2
votes
1answer
1k views

Generating all derangements of a multiset?

I'm trying to find a reference to an algorithm for generating all the derangements of a multiset (this is not my area of expertise, by the way!), and so far I have found plenty on derangements of sets,...
15
votes
3answers
1k views

What is the “correct” category of multisets

During seminar the other day, when speaking about subobject classifiers, I asked if the subobject classifier for the category of multisets would have integer truth values, corresponding to the number ...