path: root/2023/rs/code/four/src/main.rs

#![feature(array_chunks)]
#![feature(iter_array_chunks)]

static INPUT: &[u8] = include_bytes!("input.txt");

fn parse_val(s: &[u8]) -> u8 {
  (if s[0].is_ascii_digit() { (s[0] - b'0') * 10 } else { 0 }) +
  s[1] - b'0'
}

fn main() {
  let valueified = INPUT.array_chunks::<117>()
    .map(|b| {
      let win: u128 = b[10..40].array_chunks::<3>().fold(0, |a, b| a | (1 << parse_val(&b[0..2])));
      let val: u128 = b[42..].array_chunks::<3>().fold(0, |a, b| a | (1 << parse_val(&b[0..2])));
      (win & val).count_ones()
    });

  let winsum = valueified.clone().map(|c| if c == 0 { 0 } else { 2u32.pow(c - 1) }).sum::<u32>();
  println!("Sum of Win Scores: {winsum}");

  let mut nums = valueified.map(|n| (n as usize, 1)).collect::<Vec<(usize, u32)>>();
  for i in 0..nums.len() {
    let (m, c) = nums[i];
    for n in i + 1 .. (i + m + 1).min(nums.len()) {
      nums[n].1 += c;
    }
  }
  let cardsum = nums.into_iter().map(|(_, c)| c).sum::<u32>();
  println!("Sum of Recursive Card Counting: {cardsum}");
}