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90 lines
1.7 KiB
90 lines
1.7 KiB
1 year ago
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require "set"
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rocks = <<~ROCKS.split("\n\n")
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####
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.#.
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###
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.#.
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..#
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..#
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###
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#
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#
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#
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#
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##
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##
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ROCKS
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rocks = rocks
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.map {|rock| rock.lines(chomp: true).reverse.map(&:chars) }
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.map {|rock|
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rock.each.with_index.with_object(Set.new) {|(row, y), rocks|
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row.each.with_index do |c, x|
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rocks << [x, y] if c == ?#
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end
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}
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}
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rocks = rocks.cycle
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jet_pattern = ARGF.read.strip.chars
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jet_pattern = jet_pattern.cycle
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chamber = Hash.new {|_,(x,y)| !(0...7).cover?(x) || y.negative? }
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def move_rock(chamber, rock, dx, dy)
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next_rock = rock.map {|x,y| [x+dx, y+dy] }
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if next_rock.any? {|x,y| chamber[[x, y]] }
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rock
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else
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next_rock
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end
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end
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def debug(chamber, rock)
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max_y = [chamber.keys.map(&:last).max || 0, rock.map(&:last).max || 0].max
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puts
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puts max_y.downto(0).map {|y|
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(0...7).map {|x|
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(chamber[[x,y]] || rock.include?([x,y])) ? ?# : ?.
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}.join
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}.join("\n")
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end
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2022.times do
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rock = rocks.next
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y = chamber.empty? ? 3 : chamber.keys.map(&:last).max + 4
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x = 2
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rock = move_rock(chamber, rock, x, y)
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loop do
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rock = case jet = jet_pattern.next
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when ?< then move_rock(chamber, rock, -1, 0)
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when ?> then move_rock(chamber, rock, 1, 0)
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else fail "invalid jet pattern: #{jet}"
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end
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next_rock = move_rock(chamber, rock, 0, -1)
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break if rock == next_rock
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rock = next_rock
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end
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chamber.merge!(rock.to_h { [_1, true] })
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end
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# debug(chamber, Set.new)
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max_y = chamber.keys.map(&:last).max + 1
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p max_y
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candidates = (0..max_y).select {|y| (0...7).count {|x| chamber[[x,y]] } == 6 }
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# max_delta = candidates.each_cons(2).map { _2 - _1 }.max
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candidates.
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p candidates
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p max_delta
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