Generating combinations with repetitions

[Jeff Raven]

On Thu, 4 May 2000 10:29:50 +0200, Tomaz Ficko <tomaz.ficko at agroruse.si> wrote:
>This is not quite what I meant. I want it to generate combinations not
>variations, order of the elements is irrelevant.
>Example: 121 is equal to 211 or 112.
>Anyway thanks.
>
>Tomaz
>

Ah. Then perhaps the following will do.

Jeff Raven

------ Code ------

def rchoices(n, k) :
    # Returns a list consisting of all k-element subsets
    # of {1 ... n} -- with repetitions.
    result = []
    if k <= 0 :
	return result

    current = [1] * k
    while 1 :
	result.append(current[:])

	index = k - 1
	while index >= 0 :
	    if current[index] < n :
		break
	    index = index - 1
	else:
	    break
	current[index] = current[index] + 1
	while index < k - 1 :
	    current[index + 1] = current[index]
	    index = index + 1

    return result