45 lines
1.0 KiB
Lua
45 lines
1.0 KiB
Lua
local utils = require "utils"
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local puzzle1 = {}
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function puzzle1.inGrid(x, y, w, h)
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return 1 <= x and x <= w and 1 <= y and y <= h
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end
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function puzzle1.isAccessible(lines, w, h, x, y)
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local neighbors = 0
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for dy=-1, 1 do
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for dx=-1, 1 do
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if dx ~=0 or dy ~= 0 then
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local x2 = x + dx
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local y2 = y + dy
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if puzzle1.inGrid(x2, y2, w, h) then
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if lines[y2]:sub(x2, x2) == "@" then
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neighbors = neighbors + 1
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end
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end
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end
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end
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end
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return neighbors < 4
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end
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function puzzle1.solve(input)
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local lines = utils.splitLines(input)
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local accessible = 0
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local h = #lines
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local w = #lines[1]
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for y, line in ipairs(lines) do
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for x=1, #line do
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if line:sub(x, x) == "@" and puzzle1.isAccessible(lines, w, h, x, y) then
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accessible = accessible + 1
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end
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end
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end
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return accessible
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end
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return puzzle1
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