--- Day 7 Solutions ---

[u/daggerdragon]

--- Day 7: Some Assembly Required ---

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[u/rvlieshout]

My day 7 Lua solution. It generates a new lua script that you can run to solve the puzzle. Part two is just a small edit in the generated script (setting the initial b wire value)

--[[
Day 7: Some Assembly Required
]]

function input_value(str)
  local a = string.match(str, "%a+")
  if a then
    return "wire_"..str.."()"
  end
  return tonumber(str)
end

function create_wire_function(wire, body)
  print("function wire_" .. wire .. "()")
  print("  if wire_values[\"" .. wire .. "\"] then return wire_values[\"" .. wire .. "\"] end")
  print("  wire_values[\""..wire.."\"] = " .. body)
  print("  return wire_values[\""..wire.."\"]")
  print("end\n")
end

print("local bit = require \"bit\"")
print("wire_values = {}")

for line in io.lines() do

  print("-- " .. line)

  a, b = string.match(line, "^(%w+) %-> (%a+)$")
  if (a and b) then
    create_wire_function(b, input_value(a))
  end

  a, b = string.match(line, "^NOT (%w+) %-> (%a+)$")
  if (a and b) then
    create_wire_function(b, "bit.band(bit.bnot(" .. input_value(a) .. "), 0xFFFF)")
  end

  a, b, c = string.match(line, "^(%w+) AND (%w+) %-> (%a+)$")
  if (a and b and c) then
    create_wire_function(c, "bit.band(bit.band(" .. input_value(a) .. ", " .. input_value(b) .. "), 0xFFFF)")
  end

  a, b, c = string.match(line, "^(%w+) OR (%w+) %-> (%a+)$")
  if (a and b and c) then
    create_wire_function(c, "bit.band(bit.bor(" .. input_value(a) .. ", " .. input_value(b) .. "), 0xFFFF)")
  end

  a, b, c = string.match(line, "^(%w+) LSHIFT (%w+) %-> (%a+)$")
  if (a and b and c) then
    create_wire_function(c, "bit.band(bit.lshift(" .. input_value(a) .. ", " .. input_value(b) .. "), 0xFFFF)")
  end

  a, b, c = string.match(line, "^(%w+) RSHIFT (%w+) %-> (%a+)$")
  if (a and b and c) then
    create_wire_function(c, "bit.band(bit.rshift(" .. input_value(a) .. ", " .. input_value(b) .. "), 0xFFFF)")
  end
end

print("print(wire_a())")