CODEWITHSUNDEEP
rubyhashcombinatorics
xxjjnn
xxjjnn

Reputation: 15239

combinatorics in ruby with hashes

Is there a built in function or convention for when you want to do combinations of states concisely?

Given the following:

{
  animal: [:dog, :cat],
  disposition: [:grumpy, :hungry, :sleepy]
}

I want to make:

[
  {animal: :dog, disposition: :grumpy},
  {animal: :dog, disposition: :hungry},
  {animal: :dog, disposition: :sleepy},
  {animal: :cat, disposition: :grumpy},
  {animal: :cat, disposition: :hungry},
  {animal: :cat, disposition: :sleepy}
]

taking any number of input states, i.e. more than 2.

Others must have solved this before me in an elegant fashion?

Python has an array way of doing it here

Upvotes: 1

Views: 69

Answers (2)

rejin
rejin

Reputation: 179

intial hash: 

a={  
  animal: [:dog, :cat],  
  disposition: [:grumpy, :hungry, :sleepy]  
}  
b= a[:animal].product(a[:disposition]).collect do |c|
  {animal: c[0], disposition: c[1]}
end

Upvotes: 2

Ju Liu
Ju Liu

Reputation: 3999

This SO answer should work.

[{:animal=>:dog, :disposition=>:grumpy}, {:animal=>:dog, :disposition=>:hungry}, {:animal=>:dog, :disposition=>:sleepy}, {:animal=>:cat, :disposition=>:grumpy}, {:animal=>:cat, :disposition=>:hungry}, {:animal=>:cat, :disposition=>:sleepy}]

Upvotes: 1

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