~repos /plum

module aoc_2020_3

import cli
import fs

Tile =
  | TREE = True
  | EMPTY = False

slopeI() = 1
slopeJ() = 3

main() -> Unit =
  let input = fs::read_file!("./examples/test/demos/aoc2020/3.txt");
  defer input.free();
  let map = Map::parse(input);
  defer map.free();
  let tree_count = 0;
  let i = 0;
  let j = 0;
  loop {
      i += slopeI();
      j += slopeJ();
      if i == map.rows.size {
          break;
      };
      if map.get(i, j) == Tile::TREE {
          tree_count += 1;
      };
  };
  print_u32(tree_count);
  puts("\n");

Map = (
  rows: List(List(Tile))
)

Map\parse(input: String) -> Map =
  rows = listOf(List<Tile>())
  current_row = listOf<Tile>()
  for i in 0..input.len()
      c = input.char_at(i);
      if c == '#'
          current_row.push!(TREE)
      if c == '.'
          current_row.push!(EMPTY)
      if c == '\n'
          rows.push!(current_row)
          current_row = listOf<Tile>()
  Map(
    rows: rows,
  )

Map\get(i: u32, j: u32) -> Tile =
    row = rows.get!(i);
    *(row.at(j % row.size));

Map\free() -> Unit =
  for i in 0..rows.size
    row = rows.get!(i);
    row.free();
  rows.free();