Iterate over permutations without holding them in memory

Asked Oct 04 '15 at 16:09

Active Oct 06 '15 at 08:22

Viewed 555 times

Consider I have really big vector (more then 10 elements), and I have to check some stuff over each permutation, but I don't need all permutations being held in memory. Just for example, for vector with 12 elements I got memory troubles:

>> A = [1 2 3 4 5 6 7 8 9 10 11 12];
>> perms(A)
error: out of memory or dimension too large for Octave's index type

My question is: is any nice and short method to get all possible permutations over vector like iterator, without holding them all in memory, so I could to make them for arbitrary sized vector and do some stuff over each of them in a loop?

Sure I know how to programm this algorithm on any programming language, but I'm looking for ready solution on octave or Matlab.

asked Oct 04 '15 at 16:09

Andremoniy

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You probably can implement your version of this algorithm: http://stackoverflow.com/questions/1622532/algorithm-to-find-next-greater-permutation-of-a-given-string – Mohsen Nosratinia Oct 04 '15 at 19:27
@MohsenNosratinia I've already found nice solution with Heap's algorithm and will post my own answer soon – Andremoniy Oct 05 '15 at 11:20
@MohsenNosratinia If you are interested, I've published my own solution. – Andremoniy Oct 05 '15 at 15:43

Iterate over permutations without holding them in memory

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