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66 lines
1.8 KiB
66 lines
1.8 KiB
5 years ago
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rocks = {}
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pos_y = 0
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for line in io.lines(arg[1]) do
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pos_x = 0
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for char in line:gmatch(".") do
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if char == "#" then
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table.insert(rocks, {y=pos_y, x=pos_x})
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end
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pos_x = pos_x + 1
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end
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pos_y = pos_y + 1
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end
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pos_y = nil
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pos_x = nil
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max = nil
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for _, rock in ipairs(rocks) do
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count = 0
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angles_array = {}
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angles = {}
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for _, in_rock in ipairs(rocks) do
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if rock ~= in_rock then
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angle = math.atan(in_rock.y - rock.y, in_rock.x - rock.x) + math.pi / 2
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if angle < 0 then
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angle = angle + math.pi * 2
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end
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if angles[angle] == nil then
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angles[angle] = {in_rock}
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table.insert(angles_array, angle)
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count = count + 1
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else
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table.insert(angles[angle], in_rock)
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end
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end
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end
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if not max or max.count < count then
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max = {count=count, rock=rock, angles=angles, angles_array=angles_array}
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end
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end
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print(string.format("Part 1: %d (%d,%d)", max.count, max.rock.x, max.rock.y))
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table.sort(max.angles_array)
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for _, angle in ipairs(max.angles_array) do
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table.sort(max.angles[angle], function(x, y)
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local dist_x = math.sqrt((x.x - max.rock.x) ^ 2 + (x.y - max.rock.y) ^ 2)
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local dist_y = math.sqrt((y.x - max.rock.x) ^ 2 + (y.y - max.rock.y) ^ 2)
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return dist_x < dist_y
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end)
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end
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shot = 0
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while true do
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for _, angle in ipairs(max.angles_array) do
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if #max.angles[angle] > 0 then
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shot = shot + 1
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if shot >= 200 then
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rock = max.angles[angle][#max.angles[angle]]
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print(string.format("Part 2: %d", rock.x * 100 + rock.y))
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os.exit(true)
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end
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max.angles[angle][#max.angles[angle]] = nil
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end
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end
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end
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