01.rs

use std::time::Instant;

const INPUT: [i32; 100] = [56583,83363,127502,138143,113987,147407,111181,92655,79802,64636,108805,148885,51022,120002,52283,53573,142374,143523,121158,63332,63203,142400,105515,140150,89910,93081,129752,86731,128755,134756,131066,77990,77081,85779,137271,72889,117608,132442,115294,59414,75495,79459,107669,81496,144432,69138,53410,71199,141799,63964,110945,102174,87697,88838,93552,145531,54602,65080,66865,139693,98048,60409,88384,138807,130854,75997,130900,125974,129123,93480,86042,128187,74981,88144,96629,148836,124473,57616,93477,104174,97407,123017,85408,64862,85298,88142,62182,128983,62981,124580,56339,94335,125521,121373,78777,125132,94411,57789,97384,79900];

fn part_one() -> i32 {
  INPUT.iter().map(|i| i / 3 - 2).sum::<i32>()
}

fn part_two() -> i32 {
  INPUT.iter().map(|&i| {
    let (mut ans, mut mass) = (0, i);
    loop {
      mass = (mass / 3) - 2;
      if mass <= 0 { break ans; }
      ans += mass;
    }
  }).sum::<i32>()
}

fn main() {
  let now = Instant::now();
  println!("Part one: {}", part_one());
  println!("Part two: {}", part_two());
  println!("Time: {}ms", now.elapsed().as_millis());
}