75 lines
1.5 KiB
Lua
75 lines
1.5 KiB
Lua
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#!/usr/bin/env lua
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function file_exists(file)
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local f = io.open(file, "rb")
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if f then f:close() 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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function lines_from(file)
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if not file_exists(file) then return {} end
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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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function atoi_list(strings)
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local ints = {}
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for i,s in ipairs(strings) do
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ints[#ints + 1] = tonumber(s)
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end
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return ints
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end
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function toSlices(ints)
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local slices = {}
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for k,i in ipairs(ints) do
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if(k < (#ints - 1)) then
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slices[k] = ints[k] + ints[k+1] + ints[k+2]
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end
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end
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return slices
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end
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function split(s, delimiter)
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result = {};
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for match in (s..delimiter):gmatch("(.-)"..delimiter) do
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table.insert(result, match);
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end
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return result;
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end
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-------------------------------------------------
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file = "input.txt"
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local v,h,aim = 0,0,0
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allLines = lines_from(file)
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for i,l in ipairs(allLines) do
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local current = split(l, ' ')
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local cmd = current[1]
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local X = current[2]
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if(cmd == "down") then
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aim = aim + X
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end
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if(cmd == "up") then
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aim = aim - X
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end
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if(cmd == "forward") then
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h = h + X
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v = v + (aim * X)
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end
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end
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print("vertical position: " .. v)
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print("horizontal position: " .. h)
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local result = v * h
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io.write("The answer is ", result, ". Congrats, I hope!\n")
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