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49 lines
1.1 KiB
49 lines
1.1 KiB
5 years ago
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orbits = {}
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for line in io.lines(arg[1]) do
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a, b = line:match("(%w+)%)(%w+)")
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if not orbits[a] then
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orbits[a] = {}
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end
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table.insert(orbits[a], b)
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end
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print("Parsed...")
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pos_you = nil
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pos_san = nil
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function getorbits(a, branches, depth)
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local value = depth
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if not orbits[a] then
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return value
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end
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local b = branches
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if #orbits[a] > 1 then
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b = {table.unpack(branches)}
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table.insert(b, {depth=depth, name=a})
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end
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for _, orbit in ipairs(orbits[a]) do
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if orbit == "YOU" then
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pos_you = {branches=branches, depth=depth}
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end
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if orbit == "SAN" then
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pos_san = {branches=branches, depth=depth}
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end
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value = value + getorbits(orbit, b, depth + 1)
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end
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return value
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end
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print("Part 1:", getorbits("COM", {}, 0))
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commbranch = 1
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while true do
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if pos_you.branches[commbranch] ~= pos_san.branches[commbranch] then
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break
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end
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commbranch = commbranch + 1
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end
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branch = pos_you.branches[commbranch - 1]
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distance = pos_you.depth + pos_san.depth - branch.depth * 2
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print("Part 2:", distance)
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