gistfile1.rbx

#!/usr/bin/env ruby

puts '-'*10

keys = %w( 121 122 123 )

class String
def first(n=1); self[0..(n-1)]; end
end


first = keys.collect{|k|k.first}

p first.uniq == first ? 'awesome' : 'not'


second = keys.collect{|k|k.first(2)}

p second.uniq == second ? 'more awesome' : 'not'

third = keys.collect{|k|k.first(3)}

p third.uniq == third ? 'tha shiz' : 'not'

keys = %w( 111 122 133 )

n = 0
begin
  n += 1
  start = keys.collect{|k|k.first(n)}
  p start, n
end until start.uniq == start || keys == start

p start

puts '-'*10


require 'digest/md5'


keys = Array.new(10){|n| Digest::MD5.hexdigest(n.to_s) }
p keys

start_t = Time.now
n = 0
begin
  n += 1
  start = keys.collect{|k|k.first(n)}
end until start.uniq == start || keys == start

p Time.now - start_t

p start
puts start.size == keys.size

puts '-'*10

keys = Array.new(10, Digest::MD5.hexdigest('foo'))

start_t = Time.now
n = 0
begin
  n += 1
  start = keys.collect{|k|k.first(n)}
end until start.uniq == start || keys == start
p Time.now - start_t
p start