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jredville/recover_secret.rb

Created July 7, 2018 21:10
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recover_secret.rb
class Letter
include Comparable
attr_reader :before, :after
def initialize(letter)
@letter = letter
@before = []
@after = []
end
def <=>(other)
@letter <=> other
end
def before?
!@before.empty?
end
def is_before(other)
@before << other
@before.uniq!
end
def after?
!@after.empty?
end
def is_after(other)
@after << other
@after.uniq!
end
def inspect
"#<Letter(#@letter): before: #@before after: #@after>"
end
def to_str
@letter
end
end
class Triplets
attr_reader :letters
def initialize
@letters = []
end
def add(first, sec, last)
add_one first, sec, nil
add_one sec, last, first
add_one last, nil, sec
self
end
def add_letter(letter)
Letter.new(letter).tap { |let| @letters << let }
end
def find_letter(letter)
return unless letter
@letters.find(-> { add_letter letter }) { |l| l == letter }
end
def add_one(letter, before, after)
letter = find_letter letter
before = find_letter before
after = find_letter after
letter.is_before before if before
letter.is_after after if after
end
def to_s
@letters.reject(&:after?).tap do |res|
res.push find_next_letter res.last until @letters.empty?
end.join
end
def find_next_letter(letter)
letter.before.find { |let| let.after == [letter] }.tap do
letter.before.each { |bef| bef.after.delete letter }
@letters.delete letter
end
end
end
def recover_secret(triplets)
trips = triplets.reduce(Triplets.new) { |l, t| l.add(*t) }
trips.to_s
end
triplets_1 = [
['t','u','p'],
['w','h','i'],
['t','s','u'],
['a','t','s'],
['h','a','p'],
['t','i','s'],
['w','h','s']
]
puts recover_secret triplets_1
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