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#!/usr/bin/env ruby
def apply_gravity(moons)
(0...moons.count).to_a.combination(2).each do |a, b|
3.times do |i|
case moons[a][0][i] <=> moons[b][0][i]
when -1
moons[a][1][i] += 1
moons[b][1][i] -= 1
when 1
moons[b][1][i] += 1
moons[a][1][i] -= 1
end
end
end
moons
end
def update(moons)
moons.map do |moon|
[moon[0].zip(moon[1]).map(&:sum), moon[1]]
end
end
def calculate_energy(moons)
moons.map { |moon|
moon[0].map(&:abs).sum * moon[1].map(&:abs).sum
}.sum
end
input = $stdin.readlines.map(&:strip)
moons = input.map do |line|
m = line.scan(/-?\d+/)
[[m[0].to_i, m[1].to_i, m[2].to_i], [0, 0, 0]]
end
1000.times do
moons = apply_gravity(moons)
moons = update(moons)
end
puts calculate_energy(moons)
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