79 lines
1.6 KiB
Ruby
Executable File
79 lines
1.6 KiB
Ruby
Executable File
#!/usr/bin/env ruby
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require "pathname"
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require "set"
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INPUTS = [
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Pathname("inputs/test.txt"),
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Pathname("inputs/puzzle.txt"),
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].freeze
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def position_modifier(direction)
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case direction
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when ">" then [1, 0]
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when "<" then [-1, 0]
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when "^" then [0, 1]
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when "v" then [0, -1]
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end
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end
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def apply_direction(position, change)
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position.map.with_index { |v, i| v + change[i] }
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end
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def next_position(position, direction)
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apply_direction(position, position_modifier(direction))
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end
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def solve_part_1(input)
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input.lines.map do |line|
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puts " " + "-" * 10
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position = [0, 0]
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houses =
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line.chomp.each_char.each_with_object(Set[position]) do |direction, visited|
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next_pos = next_position(position, direction)
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visited.add(next_pos)
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position = next_pos
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end
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puts " Houses: #{houses.size}"
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end
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end
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def solve_part_2(input)
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input.lines.map do |line|
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puts " " + "-" * 10
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position_s = [0, 0]
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position_r = position_s.dup
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houses =
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line.chomp.each_char.each_with_object(Set[position_s.dup]).with_index(1) do |(direction, visited), index|
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if index.even?
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next_pos = next_position(position_s, direction)
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visited.add(next_pos)
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position_s = next_pos
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else
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next_pos = next_position(position_r, direction)
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visited.add(next_pos)
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position_r = next_pos
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end
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end
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puts " Houses: #{houses.size}"
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end
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end
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def main(files)
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files.each do |file|
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puts "File: #{file}"
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solve_part_1(file.read.chomp)
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puts "=" * 15
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solve_part_2(file.read.chomp)
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end
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end
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main(INPUTS)
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