58 lines
1023 B
Ruby
58 lines
1023 B
Ruby
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#!/usr/bin/env ruby
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require_relative '../common'
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class Day02 < Day
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def part1
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input.each_with_object(Position.new) { |cmd, position| position.process cmd }.result
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end
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def part2
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input.each_with_object(Position.new(use_aim: true)) { |cmd, position| position.process cmd }.result
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end
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class Position
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def initialize(use_aim: false)
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@use_aim = use_aim
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@horizontal_position = 0
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@depth = 0
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@aim = 0
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end
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def process command
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direction, value = command.match(/\A(forward|down|up) ([0-9]+)\z/).captures
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send direction, value.to_i
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end
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def result
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@horizontal_position * @depth
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end
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private
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def forward value
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@horizontal_position += value
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@depth += @aim * value if @use_aim
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end
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def down value
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if @use_aim
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@aim += value
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else
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@depth += value
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end
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end
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def up value
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if @use_aim
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@aim -= value
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else
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@depth -= value
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end
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end
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end
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end
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Day02.run
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