46 lines
810 B
Ruby
46 lines
810 B
Ruby
# frozen_string_literal: true
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input = File.readlines('./input').map do |line|
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[line[0], Integer(line[1..-1])]
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end
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$position = [0, 0]
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$waypoint = [10, 1]
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def rad(deg)
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deg * Math::PI / 180
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end
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def rotate(deg)
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x,y = $waypoint
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rad = rad(deg)
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$waypoint[0] = (x*Math.cos(rad) - y*Math.sin(rad)).round
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$waypoint[1] = (x*Math.sin(rad) + y*Math.cos(rad)).round
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end
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def move(action, value)
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case action
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when 'N'
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$waypoint[1] += value
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when 'S'
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$waypoint[1] -= value
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when 'E'
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$waypoint[0] += value
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when 'W'
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$waypoint[0] -= value
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when 'L'
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rotate(value)
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when 'R'
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rotate(-value)
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when 'F'
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$position[0] += $waypoint[0] * value
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$position[1] += $waypoint[1] * value
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end
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end
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input.each do |instr|
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move(*instr)
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end
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puts $position.values_at(0, 1).map(&:abs).sum
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