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> I need to see certain combinations for a portfolio analysis
> project I'm working on. I guess this involves a bunch of nested
> loops? For example, to obtain subsets of 4 unique numbers, I need
> 4 nested loops and then check if a, b, c, and d, hold unique
> numbers.
You just need to use 4 nested loops and make sure you DON'T choose
any repeated numbers. In pseudo-code it would look like this:
for w = 1 to 20
for x = w+1 to 20
for y = x+1 to 20
for z = y+1 to 20
print w, x, y, z
BTW Mark's formula (20.C.4) is read as "20 choose 4." You calculate
"X choose Y" as X! / (Y! * (X-Y)!), where X! is "X factorial."
Gary
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