108 lines
2.6 KiB
Ruby
108 lines
2.6 KiB
Ruby
triangle = [[75],
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[95,64],
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[17,47,82],
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[18,35,87,10],
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[20, 4,82,47,65],
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[19, 1,23,75, 3,34],
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[88, 2,77,73, 7,63,67],
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[99,65, 4,28, 6,16,70,92],
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[41,41,26,56,83,40,80,70,33],
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[41,48,72,33,47,32,37,16,94,29],
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[53,71,44,65,25,43,91,52,97,51,14],
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[70,11,33,28,77,73,17,78,39,68,17,57],
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[91,71,52,38,17,14,91,43,58,50,27,29,28],
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[63,66, 4,68,89,53,67,30,73,16,69,87,40,31],
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[ 4,62,98,27,23, 9,70,98,73,93,38,53,60, 4,23]]
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class Triangle
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def initialize(list_of_lists)
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@data = list_of_lists
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@route_length = {}
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locations.each do |location|
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@route_length[location] = @data[location.first][location.last]
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end
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end
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def locations
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locations = []
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(0..row_count-1).each do |row_num|
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(0..row_num).each do |index|
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locations << [row_num, index]
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end
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end
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locations
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end
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def row(num)
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@data[num]
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end
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def row_count
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@data.count
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end
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def route_length(row, index_from_left)
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@route_length[[row, index_from_left]]
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end
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def root
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@data.first.first
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end
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def element(row_num, index_from_left)
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row(row_num)[index_from_left]
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end
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def children_of_element(row_num, index_from_left)
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unless is_bottom_row?(row_num)
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[@route_length[[row_num+1, index_from_left]], @route_length[[row_num+1, index_from_left+1]]]
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else
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[]
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end
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end
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def is_bottom_row?(row_num)
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row_num == @data.count - 1
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end
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def bottom_row
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@data.count - 1
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end
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def maximum_route_total
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((bottom_row-1).downto(0)).each do |row_num|
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(0..@data[row_num].length-1).each do |index|
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children = children_of_element(row_num, index)
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current_elt = element(row_num, index)
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choose_first_elt = current_elt + children.first
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choose_second_elt = current_elt + children.last
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@route_length[[row_num, index]] = [choose_first_elt, choose_second_elt].max
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end
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end
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@route_length[[0,0]]
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end
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end
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def parse_triangle(filename)
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triangle_data = []
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File.open(filename, 'r') do |file|
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while line = file.gets
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triangle_data << line.split(" ").map(&:to_i)
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end
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end
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Triangle.new(triangle_data)
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end
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parsed_triangle = parse_triangle("triangle18.txt")
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triangle_two = Triangle.new([ [3],
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[7,4],
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[2,4,6],
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[8,5,9,3] ])
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triangle_67 = parse_triangle("triangle67.txt")
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puts triangle_two.maximum_route_total.inspect
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puts parsed_triangle.maximum_route_total.inspect
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puts triangle_67.maximum_route_total.inspect
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