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41 lines
722 B
41 lines
722 B
input = ARGF.read.to_i
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dir = [1,0]
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def next_dir(dir)
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case dir
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when [1,0]
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[0,1]
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when [0,1]
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[-1,0]
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when [-1,0]
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[0,-1]
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when [0,-1]
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[1,0]
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else
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raise "invalid dir: #{dir}"
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end
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end
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grid = Hash.new(0)
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grid[[0,0]] = 1
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def next_value(grid, x, y)
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[[-1, 1],[0, 1],[1,1],
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[-1, 0], [1,0],
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[-1,-1],[0,-1],[1,-1]].map {|i,j| grid[[x+i,y+j]]}.sum
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end
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current = [0,0]
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loop do
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next_square = current.zip(dir).map {|a,b| a + b }
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value = next_value(grid, *next_square)
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puts "#{current}: #{value}"
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exit if value > input
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grid[next_square] = value
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current = next_square
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dir = next_dir(dir) if grid[current.zip(next_dir(dir)).map {|a,b| a + b }] == 0
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end
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p next_value(grid, 1,0)
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