Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Say you want to iterate over a sequence [0 to n] in a random order, visiting every element exactly once. Is there any way to do this in O(1) memory, i.e. without creating an [1..n] sequence with std::iota and running it through std::random_shuffle?
Some kind of iterator spitting out the sequence in a random order would be optimal.
A requirement is that it should be possible to get another random order by picking another seed.
In theory, if you built a random number generator whose period was exactly n, and covered all values in 0..n, then running through this once would give you what you like.
Of course, this may not be a general solution, at least if you are looking for something dynamic, since you would have to pre-create the PRNG and how you do this depends on n.