input/2020/day23.txt

@@ -1 +0,0 @@
-459672813

src/day23.rs

@@ -1,86 +0,0 @@
-use aoc_runner_derive::aoc;
-
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-struct Cup(u32);
-impl Cup {
-    fn as_idx(self) -> usize {
-        self.0 as usize - 1
-    }
-
-    fn from_idx(idx: usize) -> Self {
-        Cup(idx as u32 + 1)
-    }
-}
-
-#[derive(Debug)]
-struct Cups {
-    current: Cup,
-    cups: Box<[Cup]>,
-}
-
-impl Cups {
-    fn parse(input: &[u8], total_len: usize) -> Option<Self> {
-        let mut cups = vec![Cup(0); total_len];
-        let input_iter = input.iter().map(|x| (x - b'0') as u32).chain(input.len() as u32 + 1 ..= total_len as u32);
-        for (curr, next) in input_iter.clone().zip(input_iter.cycle().skip(1)) {
-            cups[curr as usize - 1] = Cup(next as u32);
-        }
-
-        Some(Cups {
-            current: Cup((input[0] - b'0') as u32),
-            cups: cups.into_boxed_slice(),
-        })
-    }
-
-    fn do_move(&mut self) {
-        let taken_1 = self.next_cup(self.current);
-        let taken_2 = self.next_cup(taken_1);
-        let taken_3 = self.next_cup(taken_2);
-
-        let mut dest_cup =
-            Cup::from_idx((self.current.as_idx() + self.cups.len() - 1) % self.cups.len());
-        Cup(((self.current.0 as usize - 1 + self.cups.len() - 1) % self.cups.len()) as u32 + 1);
-        while dest_cup == taken_1 || dest_cup == taken_2 || dest_cup == taken_3 {
-            dest_cup = Cup::from_idx((dest_cup.as_idx() + self.cups.len() - 1) % self.cups.len());
-        }
-        self.cups[self.current.as_idx()] = self.next_cup(taken_3);
-        self.cups[taken_3.as_idx()] = self.next_cup(dest_cup);
-        self.cups[dest_cup.as_idx()] = taken_1;
-        self.current = self.next_cup(self.current);
-    }
-
-    fn next_cup(&self, cup: Cup) -> Cup {
-        self.cups[cup.as_idx()]
-    }
-
-    fn iter(&self, starting_cup: Cup) -> impl Iterator<Item = Cup> + '_ {
-        std::iter::successors(Some(starting_cup), move |&prev_cup| {
-            Some(self.next_cup(prev_cup))
-        })
-    }
-}
-
-#[aoc(day23, part1)]
-fn solve_d23_p1(input: &[u8]) -> usize {
-    let mut cups = Cups::parse(input, input.len()).unwrap();
-    for _ in 0..100 {
-        cups.do_move();
-    }
-    cups.iter(Cup(1))
-        .skip(1)
-        .take_while(|&cup| cup != Cup(1))
-        .fold(0, |accum, cup| accum * 10 + cup.0 as usize)
-}
-
-#[aoc(day23, part2)]
-fn solve_d23_p2(input: &[u8]) -> usize {
-    let mut cups = Cups::parse(input, 1_000_000).unwrap();
-    for _ in 0..10_000_000 {
-        cups.do_move();
-    }
-    cups.iter(Cup(1))
-        .skip(1)
-        .take(2)
-        .map(|x| x.0 as usize)
-        .product()
-}

src/lib.rs

@@ -13,7 +13,6 @@ pub mod day2;
 pub mod day20;
 pub mod day21;
 pub mod day22;
-pub mod day23;
 pub mod day3;
 pub mod day4;
 pub mod day5;