54 lines
923 B
Ruby
54 lines
923 B
Ruby
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#!/usr/bin/env ruby
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require "debug"
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input = (ARGV.first.nil? ? DATA : ARGF)
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.readlines(chomp: true)
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.map(&:to_i)
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def evolve(secret)
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a = ((secret * 64) ^ secret) % 16777216
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b = ((a / 32) ^ a) % 16777216
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c = ((b * 2048) ^ b) % 16777216
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end
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part_1 = input.map do |secret|
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original = secret
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2000.times { secret = evolve(secret) }
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secret
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end.sum
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p part_1
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sequences = input.map do |secret|
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secrets = 2000.times
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.map { secret = evolve(secret) }
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prices = secrets.map { _1.digits.first }
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changes = prices
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.map.with_index { |p, i| i == 0 ? 0 : p - prices[i - 1] }
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sequences = Hash.new
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changes[1..].each_cons(4).with_index.each do |sequence, i|
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sequences[sequence] ||= prices[i + 4]
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end
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sequences
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end
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unique_sequences = sequences.flat_map(&:keys).uniq
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part_2 = unique_sequences.map do |sequence|
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sequences.sum { _1.fetch(sequence, 0) }
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end.max
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p part_2
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__END__
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1
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10
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100
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2024
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