archive or wiki did not help, but perhaps I searched wrong
perm =: i.@! A. i.
~.@({~ [: perm #) 1 1 2 2
1 1 2 2
1 2 1 2
1 2 2 1
2 1 1 2
2 1 2 1
2 2 1 1
while that is the answer I want, and is short and elegant, it grows very
innefficient as the length of the argument grows even if the answer is a short
list.
Is there an algorithm that can produce these "permutations with repeats"
without the intermediate full permutation list?
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