38 lines
793 B
Lua
38 lines
793 B
Lua
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-- see if the file exists
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local function file_exists(file)
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local f = io.open(file, "rb")
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if f then
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f:close()
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end
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return f ~= nil
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end
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-- get all lines from a file, returns an empty
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-- list/table if the file does not exist
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local function lines_from(file)
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if not file_exists(file) then
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return {}
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end
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local lines = {}
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for line in io.lines(file) do
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lines[#lines + 1] = line
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end
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return lines
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end
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-- tests the functions above
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local file = "input"
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local lines = lines_from(file)
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local total = 0
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-- print all line numbers and their contents
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for _, line in pairs(lines) do
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for a, b in string.gmatch(line, "mul%((%d+),(%d+)%)") do
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---@diagnostic disable-next-line: redefined-local
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local a, b = tonumber(a), tonumber(b)
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total = total + (a * b)
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end
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end
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io.output():write(total)
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