I'm looking for a way to randomize lists in python (which I already know how to do) but to then make sure that two things aren't next to each other. For example, if I were to be seating people and numbering the listing going down by 0, 1, 2, 3, 4, 5 based on tables but 2 people couldn't sit next to each other how would I make the list organized in a way to prohibit the 2 people from sitting next to each other.
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2simply check the shuffled list you know how to create for your condition. Did you try anything?Ma0– Ma02018-06-08 11:16:42 +00:00Commented Jun 8, 2018 at 11:16
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@Ev.Kounis O(∞)? :)timgeb– timgeb2018-06-08 11:18:47 +00:00Commented Jun 8, 2018 at 11:18
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@timgeb If you construct the list instead to make sure it satisfies your condition, it is not actually random any more, is it? And i guess it is more like O(?).Ma0– Ma02018-06-08 11:23:07 +00:00Commented Jun 8, 2018 at 11:23
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@Ev.Kounis I'd call it random with respect to a constraint. You could create all the permutations of the list that satisfy the condition and then pick one randomly. One way is probably to construct a generator that enumerates these permutations and then create a random integer (edit: between 1 and #<allowed permutations>) and advance the generator as many times as that integer.timgeb– timgeb2018-06-08 11:25:21 +00:00Commented Jun 8, 2018 at 11:25
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What two things shouldn't be next to each other? This is unclear.Alper– Alper2018-06-08 11:28:23 +00:00Commented Jun 8, 2018 at 11:28
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1 Answer
As you say that you know how to shuffle a list, the only requirement is that two elements are not next to each other.
A simple way is to:
- shuffle the full list
- if the two elements are close, choose a random possible position for the second one
- exchange the two elements
Maximum cost: one shuffle, one random choice, one exchange
