CODEWITHSUNDEEP
rubyarraysmerge
Nick Ginanto
Nick Ginanto

Reputation: 32160

Zipping 2 arrays in ruby in random locations

Is there an easy way to zip 2 arrays in random locations and keep their original order?

for example

a=[0,1,2,3,4,5,6,7,8,9,10]


b=["one","two","three","four"]

and a random number from 0 to 5 with rand(5)

zipped = [0,"one",1,2,3,"two",4,"three",5,6,7,8,"four",9,10]

and the random series would be 1,3,1,4 as location to where to "zip" each element of b into a

The best I could do is

i=0
merged=a
b.each do |x|
rnd = rand(5)
merged.insert(i+rnd,x)
i=i+rnd
end

Upvotes: 4

Views: 325

Answers (2)

dbenhur
dbenhur

Reputation: 20398

Here's a variant of Mark Hubbart's approach in a more functional style.

MergeTuple = Struct.new :place, :value

def ordered_random_merge( merge_to, merge_from )
  merge_from.
  map { |e| MergeTuple[ rand( merge_to.size+1 ), e ] }.
  sort_by { |mt| - mt.place }.
  each_with_object( merge_to.dup ) { |mt, merged| merged.insert(mt.place, mt.value) }
end

Upvotes: 0

marcus erronius
marcus erronius

Reputation: 3693

This version will give a balanced shuffling, with insertions not biased to either end of the array.

def ordered_random_merge(a,b)
  a, b = a.dup, b.dup
  a.map{rand(b.size+1)}.sort.reverse.each do |index|
    b.insert(index, a.pop)
  end
  b
end

Upvotes: 4

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