Functions

boring_math.combinatorics.comb(n: int, m: int, /, target_top: int = 700, target_bot: int = 5) → int

C(n, m) - combinations

Number of ways m items can be taken from n items. Geared to works efficiently for Python’s arbitrary length integers.

param n:

Total number of distinct items to choose from.

param m:

Number of items to choose, order does not matter.

param target_top:

Config param to cancel factors before multiplying.

param target_bot:

Config param to cancel factors before multiplying.

returns:

Number of ways to choose m items from n items.

raises ValueError:

If either n < 0 or m < 0.

Note

• slower but comparable to math.comb

• default parameters geared to large values of n and m

• defaults work reasonably well for smaller (human size) values

Tip

For inner loops with smaller values, use

target_top = target_bot = 1

or just use math.comb(n, m) instead.

boring_math.combinatorics.perm(n: int, m: int, /) → int

P(n, m) - permutations

Number of orderings of m items taken from n items.

param n:

Total number of distinct items to order.

param m:

Number of items in each ordering.

returns:

Number of arrangements of m items from n items.

raises ValueError:

If either n < 0 or m < 0.

Warning

About 5 times slower than the math.perm C code.