Given a list of strings, how can I determine what the shortest length of differentiation is?

Say I have an array of hash strings, e.g.

['a04a872ff4027233', '8cef496d2a92808c', etc.]

I would like an elegant way to determ开发者_C百科ine what is the shortest uniform-length substring I can use to differentiate between the alternatives.

E.g. if the shortest length substring is 3, then the options could be abbreviated to ['a04', '8ce', etc], and I could then just expand the abbreviation later.

I need a solution in Ruby.

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(1...s.first.size).find {|i| !s.map {|j| j[0...i]}.uniq!}

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Not very "elegant" per se, but this would work:

strings = ['a04a872ff4027233', '8cef496d2a92808c', .....]
count = 1
count += 1 while strings.map{ |item| item[0...count] }.uniq.length != strings.length

count
# => 3

strings.map{ |item| item[0...count] }
# => ['a04', '8ce', ...]