On Feb 28, 4:44 pm, Arnaud Delobelle <[EMAIL PROTECTED]> wrote:
> ... here is another attempt on the same principle:
>
> ---------------
> def boxings(n, k):
> """boxings(n, k) -> iterator
>
> Generate all ways to place n indistiguishable items into k
> distinguishable boxes
> """
> seq = [n]*k + [0]
> while True:
> yield tuple(seq[i] - seq[i+1] for i in xrange(k))
> i = seq.index(0) - 1
> if i >= 1:
> seq[i:k] = [seq[i] - 1] * (k - i)
> else:
> return
Actually this is better as it handles k=0 correctly:
def boxings(n, k):
seq, i = [n]*k + [0], k
while i:
yield tuple(seq[i] - seq[i+1] for i in xrange(k))
i = seq.index(0) - 1
seq[i:k] = [seq[i] - 1] * (k-i)
--
Arnaud
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