Day 5

src/day5.rs

@@ -0,0 +1,151 @@
+static INPUT: &str = include_str!("inputs/day5.txt");
+
+type CrateID = char;
+#[derive(Debug)]
+struct Stacks(Vec<Vec<CrateID>>);
+impl Stacks {
+	fn apply_move_part_1(&mut self, mv: &Move) {
+		let from = mv.from - 1;
+		let to = mv.to - 1;
+
+		for _ in 0..mv.count {
+			let c = self.0[from].pop().unwrap();
+
+			self.0[to].push(c)
+		}
+	}
+
+	fn apply_move_part_2(&mut self, mv: &Move) {
+		let from = mv.from - 1;
+		let to = mv.to - 1;
+
+		// SAFETY: should be safe, borrowing from disjoint sub-vectors and
+		// not modifying the length of the primary vector
+		unsafe {
+			let from: &'static mut Vec<_> =
+				core::mem::transmute(&mut self.0[from]);
+
+			let new_len = from.len() - mv.count;
+			let picked_up = &from[new_len..];
+			self.0[to].extend_from_slice(picked_up);
+			from.truncate(new_len);
+		}
+	}
+}
+
+fn parse_stacks(s: &str) -> Stacks {
+	let mut lines = s.split('\n').filter(|s| !s.is_empty()).map(|line| {
+		let mut chars = line.chars();
+
+		core::iter::from_fn(move || {
+			match chars.next() {
+				None => return None,
+				Some(_) => (),
+			};
+
+			let id = chars.next().unwrap();
+			chars.next();
+			chars.next();
+
+			if id == ' ' {
+				return Some(None);
+			}
+
+			Some(Some(id))
+		})
+	});
+
+
+	let mut crates = Vec::new();
+	let first_line = lines.next().unwrap();
+	for id in first_line {
+		let mut stack = Vec::new();
+		if let Some(id) = id {
+			stack.push(id);
+		}
+
+		crates.push(stack);
+	}
+
+	for ids in lines {
+		for (idx, id) in ids.enumerate() {
+			if let Some(id) = id {
+				crates[idx].push(id);
+			}
+		}
+	}
+
+	for stack in &mut crates {
+		stack.pop();
+		stack.reverse();
+	}
+
+	Stacks(crates)
+}
+
+#[derive(Debug)]
+struct Move {
+	count: usize,
+	from: usize,
+	to: usize,
+}
+fn parse_moves(s: &str) -> impl Iterator<Item = Move> + '_ {
+	s.split('\n').filter(|s| !s.is_empty()).map(|line| {
+		let mut words = line.split(' ');
+		let count = {
+			words.next();
+			words.next().unwrap()
+		};
+		let from = {
+			words.next();
+			words.next().unwrap()
+		};
+		let to = {
+			words.next();
+			words.next().unwrap()
+		};
+
+		Move {
+			count: count.parse().unwrap(),
+			from: from.parse().unwrap(),
+			to: to.parse().unwrap(),
+		}
+	})
+}
+
+fn parse(s: &str) -> (Stacks, impl Iterator<Item = Move> + '_) {
+	let mut parts = s.split("\n\n");
+	let crates_str = parts.next().unwrap();
+	let stacks = parse_stacks(crates_str);
+
+	let moves_str = parts.next().unwrap();
+	let moves = parse_moves(moves_str);
+
+	(stacks, moves)
+}
+
+pub fn part1() {
+	let (mut stacks, moves) = parse(INPUT);
+
+	for mv in moves {
+		stacks.apply_move_part_1(&mv);
+	}
+
+	for stack in &stacks.0 {
+		print!("{}", stack.last().unwrap());
+	}
+	println!();
+}
+
+pub fn part2() {
+	let (mut stacks, moves) = parse(INPUT);
+
+	for mv in moves {
+		stacks.apply_move_part_2(&mv);
+	}
+
+	for stack in &stacks.0 {
+		print!("{}", stack.last().unwrap());
+	}
+	println!();
+}

src/inputs/day5.txt

@@ -0,0 +1,512 @@
+[F]         [L]     [M]            
+[T]     [H] [V] [G] [V]            
+[N]     [T] [D] [R] [N]     [D]    
+[Z]     [B] [C] [P] [B] [R] [Z]    
+[M]     [J] [N] [M] [F] [M] [V] [H]
+[G] [J] [L] [J] [S] [C] [G] [M] [F]
+[H] [W] [V] [P] [W] [H] [H] [N] [N]
+[J] [V] [G] [B] [F] [G] [D] [H] [G]
+ 1   2   3   4   5   6   7   8   9 
+
+move 6 from 4 to 3
+move 5 from 8 to 9
+move 1 from 4 to 5
+move 1 from 4 to 5
+move 2 from 2 to 7
+move 2 from 1 to 6
+move 9 from 6 to 1
+move 12 from 3 to 5
+move 1 from 8 to 4
+move 3 from 1 to 5
+move 1 from 6 to 7
+move 10 from 5 to 2
+move 14 from 5 to 1
+move 8 from 7 to 9
+move 11 from 2 to 9
+move 1 from 3 to 9
+move 11 from 1 to 5
+move 2 from 1 to 9
+move 1 from 4 to 8
+move 6 from 1 to 5
+move 1 from 8 to 3
+move 16 from 5 to 1
+move 4 from 1 to 3
+move 1 from 5 to 6
+move 4 from 3 to 4
+move 1 from 6 to 7
+move 21 from 9 to 6
+move 2 from 1 to 9
+move 2 from 4 to 9
+move 5 from 9 to 4
+move 9 from 1 to 6
+move 6 from 4 to 6
+move 1 from 6 to 2
+move 1 from 7 to 6
+move 1 from 3 to 2
+move 8 from 6 to 9
+move 3 from 1 to 8
+move 1 from 2 to 1
+move 13 from 6 to 3
+move 1 from 1 to 9
+move 2 from 1 to 6
+move 3 from 8 to 4
+move 4 from 4 to 9
+move 3 from 1 to 3
+move 22 from 9 to 8
+move 1 from 2 to 9
+move 6 from 8 to 9
+move 15 from 6 to 5
+move 5 from 8 to 9
+move 11 from 9 to 8
+move 13 from 5 to 1
+move 1 from 6 to 5
+move 1 from 9 to 3
+move 21 from 8 to 3
+move 3 from 5 to 3
+move 11 from 1 to 2
+move 25 from 3 to 1
+move 5 from 1 to 7
+move 20 from 1 to 7
+move 1 from 6 to 7
+move 16 from 3 to 9
+move 8 from 9 to 6
+move 1 from 1 to 5
+move 5 from 9 to 4
+move 2 from 2 to 1
+move 2 from 9 to 4
+move 1 from 9 to 4
+move 1 from 8 to 4
+move 1 from 5 to 2
+move 3 from 4 to 6
+move 1 from 4 to 7
+move 9 from 7 to 6
+move 5 from 4 to 6
+move 7 from 7 to 2
+move 1 from 1 to 6
+move 11 from 2 to 5
+move 10 from 5 to 1
+move 1 from 6 to 8
+move 1 from 5 to 7
+move 24 from 6 to 1
+move 12 from 1 to 4
+move 12 from 4 to 8
+move 2 from 2 to 7
+move 3 from 7 to 2
+move 5 from 2 to 8
+move 9 from 8 to 9
+move 9 from 8 to 5
+move 1 from 9 to 1
+move 14 from 1 to 8
+move 11 from 7 to 9
+move 4 from 1 to 3
+move 7 from 1 to 2
+move 3 from 3 to 7
+move 12 from 9 to 7
+move 8 from 7 to 2
+move 4 from 9 to 2
+move 1 from 3 to 6
+move 5 from 5 to 9
+move 14 from 2 to 1
+move 8 from 9 to 4
+move 6 from 4 to 5
+move 5 from 5 to 7
+move 1 from 8 to 2
+move 2 from 4 to 6
+move 4 from 7 to 3
+move 10 from 8 to 4
+move 2 from 3 to 6
+move 7 from 7 to 6
+move 10 from 4 to 8
+move 5 from 1 to 6
+move 8 from 2 to 1
+move 7 from 6 to 8
+move 9 from 6 to 5
+move 16 from 1 to 6
+move 2 from 3 to 9
+move 1 from 7 to 4
+move 2 from 9 to 1
+move 14 from 6 to 7
+move 1 from 6 to 3
+move 2 from 6 to 3
+move 9 from 5 to 7
+move 3 from 1 to 6
+move 3 from 3 to 7
+move 5 from 5 to 9
+move 3 from 6 to 2
+move 1 from 6 to 2
+move 12 from 8 to 2
+move 5 from 2 to 1
+move 2 from 1 to 3
+move 25 from 7 to 1
+move 1 from 4 to 6
+move 2 from 3 to 9
+move 26 from 1 to 9
+move 2 from 1 to 8
+move 1 from 6 to 8
+move 1 from 7 to 1
+move 7 from 8 to 1
+move 7 from 1 to 5
+move 1 from 1 to 2
+move 2 from 8 to 6
+move 32 from 9 to 8
+move 1 from 6 to 5
+move 5 from 2 to 9
+move 1 from 9 to 7
+move 24 from 8 to 3
+move 1 from 6 to 9
+move 3 from 2 to 5
+move 1 from 7 to 9
+move 4 from 9 to 3
+move 8 from 8 to 7
+move 18 from 3 to 7
+move 20 from 7 to 8
+move 6 from 8 to 9
+move 6 from 5 to 1
+move 8 from 9 to 4
+move 3 from 5 to 4
+move 8 from 8 to 4
+move 2 from 5 to 2
+move 3 from 1 to 5
+move 4 from 3 to 7
+move 6 from 2 to 9
+move 3 from 3 to 6
+move 6 from 4 to 5
+move 2 from 6 to 3
+move 1 from 3 to 1
+move 4 from 3 to 8
+move 8 from 4 to 3
+move 4 from 3 to 7
+move 4 from 4 to 5
+move 4 from 9 to 5
+move 3 from 3 to 4
+move 3 from 4 to 9
+move 1 from 1 to 4
+move 2 from 1 to 5
+move 7 from 7 to 8
+move 4 from 7 to 4
+move 1 from 6 to 7
+move 1 from 1 to 5
+move 1 from 3 to 8
+move 11 from 5 to 9
+move 17 from 9 to 8
+move 13 from 8 to 4
+move 1 from 4 to 8
+move 4 from 7 to 1
+move 4 from 8 to 3
+move 6 from 5 to 4
+move 3 from 3 to 6
+move 2 from 1 to 9
+move 1 from 9 to 5
+move 1 from 3 to 5
+move 5 from 5 to 9
+move 2 from 1 to 8
+move 21 from 8 to 6
+move 2 from 8 to 4
+move 4 from 9 to 6
+move 1 from 9 to 7
+move 19 from 4 to 1
+move 28 from 6 to 5
+move 7 from 4 to 2
+move 28 from 5 to 3
+move 1 from 9 to 4
+move 1 from 4 to 2
+move 1 from 7 to 8
+move 1 from 8 to 9
+move 13 from 1 to 3
+move 8 from 2 to 8
+move 3 from 1 to 2
+move 5 from 8 to 5
+move 1 from 2 to 7
+move 1 from 9 to 7
+move 1 from 2 to 3
+move 2 from 7 to 9
+move 1 from 2 to 6
+move 1 from 9 to 1
+move 9 from 3 to 9
+move 3 from 9 to 1
+move 1 from 6 to 8
+move 21 from 3 to 7
+move 7 from 9 to 4
+move 2 from 4 to 2
+move 1 from 8 to 6
+move 7 from 1 to 4
+move 7 from 7 to 8
+move 4 from 5 to 9
+move 10 from 7 to 1
+move 7 from 3 to 9
+move 1 from 7 to 9
+move 1 from 5 to 3
+move 3 from 3 to 5
+move 10 from 4 to 2
+move 1 from 3 to 7
+move 2 from 4 to 9
+move 3 from 9 to 1
+move 3 from 7 to 1
+move 1 from 6 to 4
+move 1 from 1 to 2
+move 1 from 3 to 4
+move 2 from 4 to 3
+move 1 from 7 to 4
+move 4 from 8 to 9
+move 1 from 4 to 9
+move 3 from 1 to 9
+move 12 from 1 to 7
+move 2 from 9 to 5
+move 12 from 9 to 7
+move 5 from 5 to 1
+move 1 from 8 to 5
+move 4 from 1 to 4
+move 1 from 9 to 6
+move 1 from 3 to 4
+move 3 from 8 to 3
+move 1 from 1 to 7
+move 8 from 2 to 5
+move 2 from 8 to 1
+move 10 from 7 to 1
+move 4 from 9 to 5
+move 2 from 5 to 8
+move 11 from 5 to 4
+move 6 from 7 to 2
+move 2 from 2 to 1
+move 1 from 7 to 5
+move 1 from 5 to 1
+move 2 from 4 to 8
+move 1 from 6 to 9
+move 8 from 4 to 3
+move 8 from 1 to 7
+move 7 from 1 to 2
+move 4 from 3 to 9
+move 1 from 9 to 6
+move 7 from 2 to 1
+move 5 from 2 to 3
+move 2 from 7 to 8
+move 5 from 8 to 4
+move 2 from 9 to 3
+move 1 from 8 to 1
+move 6 from 3 to 5
+move 10 from 3 to 1
+move 3 from 5 to 3
+move 3 from 2 to 1
+move 1 from 5 to 4
+move 6 from 4 to 5
+move 1 from 6 to 2
+move 3 from 4 to 7
+move 1 from 9 to 4
+move 2 from 3 to 1
+move 1 from 9 to 8
+move 1 from 3 to 7
+move 4 from 4 to 8
+move 2 from 7 to 4
+move 8 from 5 to 9
+move 2 from 8 to 6
+move 2 from 4 to 3
+move 2 from 3 to 4
+move 4 from 9 to 7
+move 1 from 8 to 7
+move 2 from 6 to 9
+move 2 from 8 to 9
+move 1 from 2 to 9
+move 1 from 7 to 8
+move 1 from 2 to 7
+move 19 from 7 to 6
+move 1 from 8 to 1
+move 2 from 4 to 8
+move 5 from 6 to 1
+move 2 from 7 to 2
+move 2 from 2 to 8
+move 2 from 1 to 8
+move 4 from 8 to 2
+move 3 from 2 to 8
+move 6 from 9 to 5
+move 8 from 6 to 3
+move 26 from 1 to 6
+move 1 from 5 to 3
+move 1 from 1 to 5
+move 8 from 3 to 1
+move 1 from 3 to 7
+move 3 from 9 to 2
+move 4 from 2 to 6
+move 26 from 6 to 1
+move 1 from 7 to 5
+move 3 from 8 to 4
+move 2 from 8 to 2
+move 7 from 1 to 2
+move 1 from 5 to 9
+move 2 from 4 to 6
+move 9 from 6 to 2
+move 18 from 1 to 7
+move 6 from 7 to 1
+move 6 from 5 to 6
+move 1 from 1 to 2
+move 19 from 2 to 7
+move 1 from 4 to 2
+move 9 from 7 to 1
+move 3 from 6 to 7
+move 1 from 9 to 4
+move 1 from 2 to 3
+move 8 from 7 to 8
+move 4 from 6 to 5
+move 2 from 6 to 3
+move 1 from 4 to 2
+move 4 from 5 to 1
+move 8 from 8 to 7
+move 17 from 7 to 8
+move 3 from 3 to 1
+move 1 from 2 to 8
+move 8 from 8 to 4
+move 8 from 8 to 7
+move 1 from 8 to 2
+move 7 from 7 to 6
+move 1 from 2 to 7
+move 5 from 7 to 8
+move 7 from 1 to 6
+move 10 from 6 to 1
+move 4 from 7 to 9
+move 3 from 9 to 7
+move 1 from 7 to 2
+move 6 from 4 to 2
+move 7 from 1 to 5
+move 4 from 2 to 5
+move 16 from 1 to 9
+move 3 from 2 to 7
+move 2 from 4 to 9
+move 4 from 1 to 6
+move 5 from 7 to 4
+move 4 from 6 to 3
+move 1 from 7 to 4
+move 1 from 6 to 9
+move 1 from 8 to 5
+move 4 from 3 to 2
+move 2 from 5 to 3
+move 3 from 6 to 2
+move 3 from 2 to 1
+move 9 from 5 to 8
+move 1 from 3 to 1
+move 10 from 8 to 1
+move 1 from 8 to 5
+move 16 from 9 to 2
+move 1 from 3 to 2
+move 12 from 1 to 9
+move 1 from 9 to 2
+move 3 from 1 to 6
+move 2 from 1 to 9
+move 3 from 6 to 8
+move 20 from 2 to 7
+move 16 from 9 to 7
+move 1 from 7 to 5
+move 2 from 5 to 9
+move 2 from 2 to 3
+move 2 from 8 to 5
+move 3 from 9 to 7
+move 2 from 5 to 2
+move 1 from 4 to 6
+move 2 from 1 to 4
+move 23 from 7 to 5
+move 4 from 8 to 5
+move 7 from 7 to 1
+move 16 from 5 to 7
+move 1 from 6 to 5
+move 1 from 2 to 4
+move 2 from 3 to 9
+move 1 from 2 to 3
+move 13 from 5 to 1
+move 1 from 3 to 8
+move 1 from 9 to 4
+move 19 from 1 to 9
+move 2 from 1 to 9
+move 22 from 9 to 8
+move 14 from 8 to 5
+move 12 from 5 to 3
+move 21 from 7 to 9
+move 14 from 9 to 7
+move 1 from 8 to 6
+move 9 from 3 to 7
+move 1 from 3 to 2
+move 4 from 4 to 1
+move 1 from 2 to 4
+move 1 from 3 to 9
+move 6 from 8 to 9
+move 4 from 1 to 7
+move 2 from 5 to 9
+move 6 from 4 to 5
+move 4 from 7 to 4
+move 1 from 5 to 3
+move 5 from 9 to 7
+move 2 from 3 to 1
+move 6 from 9 to 6
+move 1 from 1 to 6
+move 2 from 4 to 2
+move 8 from 7 to 5
+move 20 from 7 to 5
+move 2 from 5 to 6
+move 4 from 9 to 5
+move 1 from 1 to 3
+move 1 from 3 to 4
+move 1 from 2 to 7
+move 1 from 4 to 9
+move 9 from 6 to 3
+move 2 from 4 to 3
+move 28 from 5 to 3
+move 1 from 8 to 3
+move 1 from 8 to 1
+move 1 from 2 to 8
+move 1 from 6 to 2
+move 1 from 8 to 1
+move 6 from 5 to 7
+move 1 from 5 to 1
+move 1 from 9 to 2
+move 1 from 1 to 3
+move 1 from 9 to 7
+move 2 from 1 to 2
+move 11 from 3 to 8
+move 3 from 8 to 6
+move 3 from 6 to 9
+move 25 from 3 to 7
+move 4 from 3 to 8
+move 4 from 2 to 3
+move 9 from 8 to 9
+move 2 from 3 to 7
+move 3 from 8 to 2
+move 11 from 9 to 7
+move 1 from 9 to 1
+move 4 from 7 to 3
+move 1 from 1 to 5
+move 23 from 7 to 2
+move 12 from 2 to 3
+move 2 from 3 to 9
+move 12 from 2 to 1
+move 2 from 3 to 9
+move 1 from 5 to 4
+move 1 from 2 to 5
+move 1 from 9 to 4
+move 1 from 5 to 9
+move 2 from 4 to 2
+move 3 from 1 to 4
+move 1 from 2 to 1
+move 10 from 3 to 2
+move 7 from 7 to 3
+move 11 from 7 to 9
+move 5 from 3 to 1
+move 1 from 4 to 5
+move 11 from 2 to 3
+move 9 from 9 to 3
+move 3 from 9 to 4
+move 2 from 4 to 8
+move 1 from 5 to 6
+move 13 from 1 to 5
+move 3 from 3 to 8
+move 3 from 7 to 2
+move 1 from 7 to 4
+move 3 from 8 to 3
+move 8 from 3 to 8
+move 4 from 4 to 5
+move 2 from 8 to 2
+move 8 from 8 to 3
+move 1 from 6 to 3
+move 2 from 2 to 8
+move 6 from 5 to 2
+move 3 from 2 to 8
+move 1 from 1 to 7
+move 2 from 9 to 3
+move 3 from 5 to 4
+move 2 from 8 to 6

src/main.rs

@@ -1,5 +1,12 @@
+#![allow(dead_code)]
+
 mod day1;
+mod day2;
+mod day3;
+mod day4;
+mod day5;
+mod util;
 
 fn main() {
-	day1::b::go();
+	day5::part2();
 }