advent-of-code/2015/day-14/main.rb

57 lines
1.5 KiB
Ruby
Executable File

#!/usr/bin/env ruby
# frozen_string_literal: true
require "pathname"
Item = Struct.new(:name, :speed, :active_time, :recovery_time)
def parse_file(file)
file.each_line.map do |line|
line.partition(" can fly ") => [name, _, tail]
tail.partition(" km/s for ") => [speed, _, tail]
tail.partition(" seconds, but then must rest for ") => [active_time, _, tail]
tail.split.first => recovery_time
Item.new(name, speed.to_i, active_time.to_i, recovery_time.to_i)
end
end
def race(items, time)
active_times = items.map { |i| [i, 1..i.active_time] }.to_h
(1..time).each_with_object(items.map {|i| [i, {score: 0, distance: 0}] }.to_h) do |sec, stats|
stats.each do |item, stat|
active = active_times[item]
stat[:distance] += item.speed if active.include?(sec)
next unless sec > active.last
active_start = sec + item.recovery_time
active_end = active_start - 1 + item.active_time
active_times[item] = active_start..active_end
end
leading = stats.values.max_by { |v| v[:distance] }[:distance]
stats.each do |n, s|
s[:score] += 1 if s[:distance] == leading
end
end
end
def main(file_paths)
file_paths.each do |file_path|
puts "File: #{file_path}"
items = parse_file(file_path)
results = race(items, 2503)
results.values.max_by { |v| v[:distance] } => {distance:}
puts "solution 1: #{distance}"
results.values.max_by { |v| v[:score] } => {score:}
puts "solution 2: #{score}"
end
end
main(ARGV.map { |x| Pathname(x) })