diff --git a/2018/rust/src/bin/day_14.rs b/2018/rust/src/bin/day_14.rs
index c7afbec..f44edbb 100644
--- a/2018/rust/src/bin/day_14.rs
+++ b/2018/rust/src/bin/day_14.rs
@@ -4,40 +4,63 @@ use advent_of_code::main;
main!();
-fn solve(_input: &str) -> Result<String, Box<Error>> {
+fn solve(input: &str) -> Result<String, Box<Error>> {
let elves = vec![0, 1];
- let recipes = vec![3, 7];
- let mut scoreboard = Scoreboard { elves, recipes };
+ let recipes = "37".into();
+ let scoreboard = Scoreboard { elves, recipes };
+
+ let needle = input;
+ // let recipes = scoreboard.find(|x| x.len() > n + 9).unwrap();
+ // let score: String = recipes[n..n + 10].iter().map(|&x| x.to_string()).collect();
+
+ let n = scoreboard
+ .scan(0, |n, recipes| {
+ let seen = *n;
+ *n = recipes
+ .len()
+ .checked_sub(needle.len() - 1)
+ .unwrap_or_else(|| 0);
+ Some((seen, recipes[seen..recipes.len()].to_string()))
+ })
+ // .inspect(|x| println!("{:?}", x))
+ .flat_map(|(n, x)| x.find(needle).map(|i| n + i))
+ .next()
+ .unwrap();
- let n = 919_901;
- let recipes = scoreboard.find(|x| x.len() > n + 9).unwrap();
- let score: String = recipes[n..n + 10].iter().map(|&x| x.to_string()).collect();
+ Ok(n.to_string())
+}
- Ok(score)
+#[test]
+fn test_solve() {
+ // Part Two
+ assert_eq!(&solve("51589").unwrap(), "9");
+ assert_eq!(&solve("01245").unwrap(), "5");
+ assert_eq!(&solve("92510").unwrap(), "18");
+ assert_eq!(&solve("59414").unwrap(), "2018");
}
#[derive(Debug)]
struct Scoreboard {
elves: Vec<usize>,
- recipes: Vec<usize>,
+ recipes: String,
}
impl Iterator for Scoreboard {
- type Item = Vec<usize>;
+ type Item = String;
fn next(&mut self) -> Option<Self::Item> {
- self.elves
- .iter()
- .map(|&x| self.recipes[x])
- .sum::<usize>()
- .to_string()
- .chars()
- .map(|x| x.to_digit(10).unwrap() as usize)
- .for_each(|x| self.recipes.push(x));
+ self.recipes.push_str(
+ &self
+ .elves
+ .iter()
+ .map(|&x| self.recipes[x..=x].parse::<usize>().unwrap())
+ .sum::<usize>()
+ .to_string(),
+ );
self.elves = self
.elves
.iter()
- .map(|&x| (1 + self.recipes[x] + x) % self.recipes.len())
+ .map(|&x| (1 + self.recipes[x..=x].parse::<usize>().unwrap() + x) % self.recipes.len())
.collect();
Some(self.recipes.clone())
@@ -47,9 +70,9 @@ impl Iterator for Scoreboard {
#[test]
fn test_scoreboard() {
let elves = vec![0, 1];
- let recipes = vec![3, 7];
+ let recipes = "37".into();
let mut scoreboard = Scoreboard { elves, recipes };
let recipes = scoreboard.next().unwrap();
- assert_eq!(recipes, vec![3, 7, 1, 0]);
+ assert_eq!(recipes, "3710");
}