List Commands Library for 50g

[Joe Horn]

(08-31-2017 11:53 PM)DavidM Wrote:  The number of combinations of n elements taken m at a time is mathematically defined as: \[C_{n,m} = \frac{n!}{m!\cdot(n-m)!}\]

This is the same equation that the built-in COMB command uses.

Not possible, for two reasons:

Reason 1:
999 995 COMB --> 41251456251 (correct) in 0.042 seconds.
But 999! alone takes 28.8 seconds. COMB can't be using factorials.

Reason 2:
999. 995. COMB --> 41251456251. (correct)
But 999.! overflows. COMB can't be using factorials.

My gut feeling is that COMB's speed and accuracy suggest that it's calculating COMB(999,995) in this order (straight through, left to right):

999/1*998/2*997/3*996/4.