~repos /plum

module aoc2020_1

import std/fs
import std/int

main() -> Unit =
  input = fs.readFile!("./examples/test/demos/aoc2020/1.txt")
  numbers = parseNumbers(input)
  for i in 0...numbers.size
    a = numbers.get!<u32>(i)
    for j in 0...numbers.size
      b = numbers.get!<u32>(j)
      if a + b == 2020
        printLn(a * b)
        return

parseNumbers(input: Str) -> List<Int> =
  numbers = List<Int>()
  current_number = 0
  for i in 0..input.length()
    c = input.charAt(i)
    if c >= '0' && c <= '9'
      current_number *= 10
      current_number += Int(c - '0')
    if c == '\n'
      numbers.push!<u32>(current_number)
      current_number = 0
  numbers