Combinatorics

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FlexRule.Extensions.Combinatorics

Calculates different arrangements of a set. for more information about the math behind check this paper.

Let’s say we have the following list:

permutations

Permutations are arrangements of objects (with or without repetition), the order does matter

 permutations (list, repeat)

• Sample: A = [a,b,c]
• permutations(A,true)
• Result:

combinations

Combinations are selections of objects, with or without repetition, the order does not matter.

 combinations (list, number, repeat)

• Sample: A = [a,b,c]
• combinations(A, 2, true)
• Result:

1	2
a	a
a	b
a	c
b	b
b	c
c	c

---

• combination(A, 2, false)
• Result:

1	2
a	b
a	c
b	c

variations

Variations are arrangements of selections of objects, where the order of the selected objects matters.

 variations (list, number, repeat)

• Sample: A=[a,b,c]
• variations(A, 2,true)
• Result:

1	2
a	a
a	b
a	c
b	a
b	b
b	c
c	a
c	b
c	c

---

• variations(A, 2, false)
• Result:

1	2
a	b
a	c
b	a
c	a
b	c
c	b