adventofcode2022/day3/day3ai.lua

for i = 1, 1000 do
-- Open the file for reading
local file = assert(io.open("strings.txt", "r"))

-- Initialize a variable to store the sum of scores
local score = 0

-- Read each line from the file
for line in file:lines() do
  -- Split the line in half
  local first_half = line:sub(1, #line / 2)
  local second_half = line:sub(#line / 2 + 1)

  -- Create a table to store the characters in each half
  local first_half_chars = {}
  local second_half_chars = {}

  -- Iterate over each character in each half and store it in the table
  for i = 1, #first_half do
    first_half_chars[first_half:sub(i, i)] = true
  end
  for i = 1, #second_half do
    second_half_chars[second_half:sub(i, i)] = true
  end

  -- Create a table to store the characters that have already been counted
  local counted_chars = {}

  -- Iterate over each character in the first half again
  -- and check if it exists in the second half
  for i = 1, #first_half do
    local char = first_half:sub(i, i)
    if second_half_chars[char] and not counted_chars[char] then
      -- If it does and it hasn't been counted yet,
      -- assign it a score and add it to the sum of scores
      local score_value = 0
      if char:lower() == char then
        -- If the character is lowercase, its score is its ASCII value - 96
        score_value = string.byte(char) - 96
      else
        -- If the character is uppercase, its score is its ASCII value - 64 + 26
        score_value = string.byte(char) - 64 + 26
      end
      score = score + score_value

      -- Add the character to the counted_chars table so it won't be counted again
      counted_chars[char] = true
    end
  end
end

-- Print the final sum of scores
print(score)
end