Rust Day 5 - Awful, awful, horrible, evil parsing

rust/Cargo.lock

@@ -4,4 +4,4 @@ version = 3
 
 [[package]]
 name = "advent-of-code"
-version = "22.4.2"
+version = "22.5.2"

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "advent-of-code"
-version = "22.4.2"
+version = "22.5.2"
 edition = "2021"
 resolver = "2"
 
@@ -38,3 +38,7 @@ path = "src/day03/main.rs"
 [[bin]]
 name = "day04"
 path = "src/day04/main.rs"
+
+[[bin]]
+name = "day05"
+path = "src/day05/main.rs"

rust/src/day05/input.txt

@@ -0,0 +1,514 @@
+        [G]         [D]     [Q]    
+[P]     [T]         [L] [M] [Z]    
+[Z] [Z] [C]         [Z] [G] [W]    
+[M] [B] [F]         [P] [C] [H] [N]
+[T] [S] [R]     [H] [W] [R] [L] [W]
+[R] [T] [Q] [Z] [R] [S] [Z] [F] [P]
+[C] [N] [H] [R] [N] [H] [D] [J] [Q]
+[N] [D] [M] [G] [Z] [F] [W] [S] [S]
+ 1   2   3   4   5   6   7   8   9 
+
+move 7 from 6 to 8
+move 5 from 2 to 6
+move 2 from 4 to 1
+move 1 from 4 to 5
+move 5 from 7 to 6
+move 7 from 6 to 3
+move 5 from 9 to 2
+move 6 from 2 to 3
+move 2 from 7 to 9
+move 20 from 3 to 1
+move 11 from 1 to 6
+move 1 from 9 to 8
+move 3 from 8 to 2
+move 8 from 1 to 5
+move 10 from 8 to 4
+move 7 from 6 to 4
+move 1 from 8 to 3
+move 8 from 1 to 7
+move 16 from 4 to 8
+move 1 from 9 to 8
+move 1 from 5 to 2
+move 4 from 7 to 4
+move 5 from 6 to 7
+move 1 from 6 to 1
+move 8 from 7 to 4
+move 1 from 6 to 9
+move 12 from 4 to 5
+move 3 from 2 to 5
+move 1 from 6 to 2
+move 1 from 3 to 7
+move 1 from 3 to 2
+move 1 from 9 to 3
+move 1 from 7 to 8
+move 1 from 7 to 5
+move 1 from 3 to 2
+move 4 from 5 to 7
+move 5 from 5 to 7
+move 1 from 4 to 3
+move 1 from 3 to 9
+move 3 from 1 to 8
+move 1 from 9 to 1
+move 2 from 2 to 1
+move 2 from 2 to 7
+move 8 from 8 to 1
+move 3 from 5 to 2
+move 8 from 7 to 5
+move 7 from 1 to 3
+move 3 from 1 to 7
+move 1 from 1 to 5
+move 1 from 3 to 7
+move 7 from 5 to 8
+move 2 from 2 to 8
+move 1 from 3 to 2
+move 1 from 2 to 4
+move 1 from 4 to 8
+move 13 from 8 to 1
+move 13 from 5 to 9
+move 2 from 5 to 2
+move 7 from 9 to 3
+move 12 from 8 to 3
+move 4 from 9 to 3
+move 1 from 3 to 4
+move 2 from 2 to 3
+move 1 from 1 to 6
+move 1 from 2 to 3
+move 1 from 5 to 9
+move 7 from 7 to 4
+move 10 from 1 to 8
+move 1 from 1 to 4
+move 1 from 9 to 5
+move 2 from 5 to 1
+move 1 from 6 to 5
+move 3 from 8 to 9
+move 5 from 4 to 3
+move 4 from 4 to 1
+move 7 from 1 to 6
+move 2 from 5 to 7
+move 35 from 3 to 4
+move 4 from 9 to 1
+move 19 from 4 to 8
+move 1 from 7 to 6
+move 1 from 9 to 2
+move 10 from 4 to 5
+move 2 from 4 to 7
+move 3 from 4 to 3
+move 1 from 2 to 8
+move 1 from 1 to 9
+move 3 from 3 to 6
+move 4 from 8 to 6
+move 4 from 5 to 2
+move 2 from 8 to 3
+move 3 from 5 to 9
+move 12 from 6 to 1
+move 8 from 8 to 6
+move 2 from 9 to 1
+move 1 from 4 to 1
+move 1 from 3 to 8
+move 3 from 7 to 8
+move 2 from 9 to 7
+move 1 from 6 to 7
+move 10 from 6 to 8
+move 4 from 2 to 5
+move 1 from 3 to 7
+move 7 from 5 to 7
+move 13 from 8 to 1
+move 29 from 1 to 4
+move 8 from 7 to 8
+move 1 from 1 to 3
+move 3 from 7 to 6
+move 1 from 1 to 9
+move 15 from 4 to 1
+move 1 from 3 to 6
+move 10 from 1 to 6
+move 10 from 6 to 7
+move 1 from 4 to 9
+move 1 from 9 to 1
+move 1 from 9 to 7
+move 6 from 7 to 8
+move 1 from 1 to 6
+move 5 from 6 to 5
+move 21 from 8 to 9
+move 5 from 1 to 9
+move 2 from 9 to 5
+move 3 from 5 to 6
+move 3 from 7 to 9
+move 4 from 4 to 6
+move 6 from 8 to 7
+move 6 from 6 to 3
+move 2 from 7 to 9
+move 1 from 7 to 2
+move 6 from 3 to 2
+move 1 from 6 to 4
+move 4 from 5 to 9
+move 1 from 4 to 5
+move 9 from 4 to 6
+move 7 from 6 to 4
+move 10 from 9 to 2
+move 5 from 7 to 5
+move 10 from 2 to 7
+move 2 from 5 to 4
+move 2 from 5 to 9
+move 4 from 9 to 4
+move 1 from 8 to 6
+move 7 from 7 to 2
+move 1 from 5 to 4
+move 2 from 7 to 1
+move 1 from 5 to 7
+move 3 from 6 to 2
+move 4 from 4 to 5
+move 1 from 2 to 7
+move 10 from 4 to 7
+move 3 from 7 to 3
+move 17 from 9 to 4
+move 1 from 1 to 4
+move 1 from 1 to 5
+move 5 from 2 to 7
+move 1 from 9 to 2
+move 5 from 4 to 8
+move 2 from 9 to 7
+move 4 from 8 to 1
+move 3 from 4 to 8
+move 1 from 2 to 5
+move 1 from 9 to 2
+move 6 from 4 to 8
+move 3 from 7 to 5
+move 1 from 4 to 9
+move 1 from 9 to 1
+move 3 from 1 to 9
+move 4 from 8 to 5
+move 2 from 9 to 8
+move 4 from 2 to 5
+move 8 from 7 to 2
+move 5 from 8 to 5
+move 2 from 7 to 8
+move 1 from 3 to 5
+move 1 from 1 to 2
+move 1 from 1 to 6
+move 2 from 3 to 6
+move 5 from 2 to 8
+move 4 from 7 to 1
+move 7 from 8 to 5
+move 1 from 1 to 5
+move 3 from 8 to 3
+move 1 from 9 to 3
+move 7 from 2 to 3
+move 2 from 2 to 8
+move 2 from 4 to 8
+move 1 from 8 to 5
+move 1 from 1 to 4
+move 2 from 4 to 7
+move 2 from 7 to 1
+move 3 from 2 to 3
+move 3 from 5 to 2
+move 1 from 8 to 3
+move 3 from 3 to 2
+move 5 from 2 to 1
+move 17 from 5 to 8
+move 9 from 8 to 1
+move 11 from 3 to 5
+move 8 from 8 to 5
+move 2 from 8 to 5
+move 16 from 1 to 4
+move 13 from 4 to 7
+move 6 from 5 to 2
+move 2 from 4 to 8
+move 5 from 7 to 9
+move 2 from 1 to 2
+move 7 from 7 to 1
+move 1 from 1 to 4
+move 1 from 9 to 8
+move 7 from 2 to 8
+move 1 from 4 to 7
+move 2 from 9 to 4
+move 1 from 4 to 1
+move 1 from 3 to 5
+move 2 from 9 to 8
+move 11 from 8 to 7
+move 2 from 6 to 5
+move 1 from 6 to 9
+move 1 from 1 to 9
+move 1 from 9 to 1
+move 4 from 1 to 4
+move 2 from 1 to 8
+move 1 from 1 to 2
+move 1 from 9 to 5
+move 2 from 4 to 3
+move 2 from 2 to 7
+move 2 from 3 to 9
+move 1 from 9 to 1
+move 1 from 9 to 1
+move 5 from 5 to 1
+move 19 from 5 to 6
+move 5 from 1 to 4
+move 1 from 2 to 9
+move 1 from 1 to 3
+move 7 from 5 to 8
+move 1 from 3 to 6
+move 8 from 7 to 3
+move 7 from 4 to 8
+move 3 from 8 to 5
+move 1 from 4 to 1
+move 1 from 9 to 4
+move 1 from 4 to 9
+move 1 from 5 to 2
+move 2 from 5 to 6
+move 2 from 8 to 2
+move 7 from 8 to 1
+move 1 from 1 to 7
+move 3 from 6 to 9
+move 2 from 3 to 2
+move 1 from 2 to 1
+move 1 from 8 to 7
+move 2 from 9 to 6
+move 2 from 9 to 5
+move 1 from 5 to 6
+move 1 from 2 to 8
+move 2 from 1 to 7
+move 1 from 4 to 3
+move 3 from 2 to 5
+move 7 from 1 to 3
+move 10 from 3 to 4
+move 3 from 5 to 4
+move 1 from 3 to 8
+move 3 from 3 to 2
+move 1 from 8 to 1
+move 1 from 1 to 3
+move 3 from 8 to 3
+move 5 from 4 to 6
+move 1 from 2 to 3
+move 4 from 6 to 4
+move 1 from 5 to 7
+move 4 from 3 to 4
+move 1 from 2 to 8
+move 12 from 7 to 6
+move 1 from 8 to 2
+move 2 from 2 to 7
+move 1 from 8 to 4
+move 23 from 6 to 3
+move 14 from 3 to 6
+move 15 from 4 to 6
+move 1 from 8 to 6
+move 10 from 3 to 7
+move 2 from 4 to 2
+move 11 from 7 to 8
+move 2 from 2 to 6
+move 44 from 6 to 9
+move 21 from 9 to 3
+move 12 from 3 to 6
+move 1 from 7 to 4
+move 1 from 4 to 7
+move 9 from 3 to 2
+move 2 from 8 to 6
+move 3 from 2 to 4
+move 17 from 9 to 1
+move 3 from 4 to 6
+move 2 from 2 to 9
+move 4 from 9 to 2
+move 10 from 6 to 9
+move 1 from 7 to 6
+move 4 from 9 to 5
+move 4 from 2 to 4
+move 14 from 1 to 5
+move 4 from 4 to 3
+move 3 from 2 to 9
+move 9 from 9 to 7
+move 1 from 2 to 5
+move 9 from 8 to 5
+move 8 from 7 to 2
+move 4 from 3 to 8
+move 5 from 6 to 2
+move 3 from 1 to 6
+move 1 from 7 to 1
+move 4 from 2 to 4
+move 3 from 6 to 4
+move 3 from 8 to 3
+move 13 from 5 to 2
+move 2 from 3 to 5
+move 12 from 5 to 9
+move 1 from 3 to 5
+move 1 from 5 to 9
+move 1 from 8 to 3
+move 4 from 9 to 5
+move 6 from 4 to 5
+move 12 from 9 to 7
+move 1 from 9 to 3
+move 1 from 3 to 2
+move 12 from 5 to 6
+move 12 from 7 to 2
+move 1 from 3 to 7
+move 1 from 4 to 8
+move 33 from 2 to 8
+move 1 from 7 to 5
+move 1 from 1 to 2
+move 4 from 5 to 4
+move 3 from 2 to 5
+move 34 from 8 to 6
+move 1 from 4 to 3
+move 1 from 5 to 7
+move 1 from 7 to 5
+move 3 from 4 to 9
+move 2 from 9 to 7
+move 1 from 9 to 4
+move 1 from 3 to 7
+move 1 from 5 to 8
+move 1 from 5 to 1
+move 1 from 5 to 7
+move 1 from 4 to 8
+move 1 from 1 to 4
+move 1 from 4 to 2
+move 3 from 7 to 5
+move 2 from 8 to 5
+move 1 from 2 to 8
+move 4 from 6 to 2
+move 1 from 8 to 6
+move 1 from 7 to 9
+move 29 from 6 to 7
+move 4 from 2 to 3
+move 2 from 5 to 8
+move 1 from 9 to 5
+move 2 from 8 to 1
+move 23 from 7 to 5
+move 2 from 6 to 1
+move 23 from 5 to 6
+move 1 from 3 to 6
+move 4 from 5 to 9
+move 2 from 1 to 3
+move 5 from 3 to 8
+move 2 from 6 to 5
+move 2 from 1 to 4
+move 1 from 9 to 8
+move 1 from 9 to 1
+move 1 from 4 to 6
+move 2 from 5 to 6
+move 6 from 7 to 8
+move 2 from 9 to 2
+move 18 from 6 to 5
+move 21 from 6 to 4
+move 1 from 1 to 6
+move 2 from 6 to 7
+move 2 from 7 to 9
+move 2 from 2 to 8
+move 7 from 4 to 3
+move 12 from 5 to 3
+move 1 from 9 to 5
+move 1 from 9 to 4
+move 6 from 5 to 2
+move 17 from 3 to 4
+move 3 from 4 to 3
+move 1 from 2 to 4
+move 5 from 2 to 8
+move 1 from 5 to 8
+move 19 from 8 to 7
+move 1 from 3 to 6
+move 1 from 8 to 4
+move 1 from 6 to 1
+move 15 from 4 to 6
+move 1 from 1 to 4
+move 3 from 3 to 5
+move 4 from 6 to 7
+move 1 from 4 to 7
+move 10 from 6 to 7
+move 16 from 4 to 5
+move 24 from 7 to 2
+move 8 from 7 to 8
+move 1 from 4 to 2
+move 6 from 8 to 7
+move 1 from 8 to 7
+move 1 from 6 to 9
+move 14 from 5 to 4
+move 9 from 7 to 8
+move 4 from 5 to 1
+move 2 from 1 to 5
+move 3 from 8 to 6
+move 2 from 6 to 9
+move 2 from 2 to 8
+move 6 from 2 to 7
+move 3 from 4 to 6
+move 1 from 3 to 4
+move 3 from 5 to 7
+move 1 from 6 to 9
+move 5 from 7 to 2
+move 4 from 9 to 1
+move 1 from 7 to 9
+move 9 from 8 to 4
+move 5 from 1 to 2
+move 2 from 6 to 1
+move 6 from 4 to 7
+move 1 from 7 to 3
+move 1 from 3 to 9
+move 1 from 9 to 7
+move 1 from 6 to 7
+move 9 from 4 to 5
+move 7 from 7 to 9
+move 3 from 7 to 5
+move 1 from 9 to 2
+move 6 from 9 to 8
+move 4 from 4 to 5
+move 1 from 4 to 2
+move 1 from 4 to 2
+move 2 from 1 to 2
+move 1 from 9 to 8
+move 10 from 2 to 4
+move 8 from 2 to 7
+move 12 from 2 to 9
+move 6 from 7 to 4
+move 1 from 1 to 2
+move 8 from 9 to 8
+move 7 from 5 to 1
+move 9 from 4 to 3
+move 14 from 8 to 4
+move 1 from 8 to 4
+move 1 from 1 to 5
+move 1 from 5 to 2
+move 3 from 2 to 4
+move 1 from 7 to 1
+move 1 from 7 to 3
+move 2 from 1 to 7
+move 3 from 5 to 7
+move 2 from 7 to 6
+move 1 from 6 to 5
+move 3 from 7 to 1
+move 1 from 6 to 8
+move 1 from 8 to 7
+move 1 from 3 to 6
+move 1 from 7 to 1
+move 4 from 1 to 4
+move 6 from 3 to 2
+move 3 from 1 to 2
+move 3 from 3 to 6
+move 3 from 2 to 6
+move 6 from 6 to 5
+move 1 from 1 to 4
+move 1 from 9 to 6
+move 5 from 2 to 1
+move 3 from 1 to 2
+move 2 from 9 to 8
+move 3 from 1 to 5
+move 1 from 9 to 7
+move 25 from 4 to 1
+move 1 from 1 to 7
+move 2 from 8 to 3
+move 13 from 1 to 9
+move 2 from 3 to 5
+move 8 from 5 to 9
+move 4 from 2 to 1
+move 2 from 6 to 7
+move 10 from 5 to 9
+move 4 from 7 to 2
+move 2 from 2 to 3
+move 9 from 9 to 2
+move 4 from 4 to 5
+move 4 from 5 to 4
+move 5 from 1 to 4
+move 10 from 4 to 5
+move 22 from 9 to 1
+move 2 from 2 to 7
+move 3 from 2 to 1
+move 6 from 2 to 6
+move 1 from 7 to 1
+move 10 from 5 to 7
+move 15 from 1 to 4
+move 13 from 1 to 5
+move 3 from 6 to 8
+move 1 from 8 to 9

rust/src/day05/main.rs

@@ -0,0 +1,153 @@
+#![feature(iter_array_chunks)]
+
+const INPUT: &str = include_str!("input.txt");
+
+mod part_1;
+use part_1::part_1;
+mod part_2;
+use part_2::part_2;
+
+#[derive(Debug, Clone)]
+pub(crate) struct Instruction {
+    origin: usize,
+    destination: usize,
+    amount: usize,
+}
+
+impl std::fmt::Display for Instruction {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "move {} from {} to {}",
+            self.amount, self.origin, self.destination
+        )
+    }
+}
+
+#[derive(Debug, Clone)]
+pub(crate) struct ChallengeInput {
+    initial_state: Vec<Vec<char>>,
+    instructions: Vec<Instruction>,
+}
+
+fn parse_input(input: &'static str) -> ChallengeInput {
+    let (unparsed_instructions, unparsed_initial_state) = input
+        .lines()
+        .partition::<Vec<_>, _>(|line| line.starts_with("move"));
+
+    let mut initial_state = vec![];
+    unparsed_initial_state
+        .iter()
+        .rev()
+        .filter(|line| line.contains('['))
+        .for_each(|line| {
+            let mut array_chunks = line.chars().array_chunks::<4>();
+            let mut idx = 0;
+            loop {
+                let Some([lbracket, char, _rbracket, _space]) = array_chunks.next() else {
+                    break;
+                };
+                for _ in 0..usize::saturating_sub(1 + 1 + idx, initial_state.len()) {
+                    initial_state.push(vec![]);
+                }
+
+                if lbracket != '[' {
+                    idx += 1;
+                    continue;
+                }
+
+                initial_state[idx].push(char);
+                idx += 1;
+            }
+            let remainder = array_chunks.into_remainder().unwrap().collect::<Vec<_>>();
+            let last_char = remainder[1];
+            drop(remainder);
+            if last_char != ' ' {
+                let length = initial_state.len();
+                initial_state[length - 1].push(last_char);
+            }
+        });
+
+    let instructions = unparsed_instructions
+        .iter()
+        .map(|instruction| {
+            // println!("instruction={instruction}");
+            let mut chars = instruction.chars().peekable();
+            loop {
+                if match chars.peek() {
+                    None => true,
+                    Some(char) => char.is_numeric(),
+                } {
+                    break;
+                }
+                chars.next();
+            }
+            let mut amount = String::new();
+            loop {
+                if match chars.peek() {
+                    None => true,
+                    Some(char) => !char.is_numeric(),
+                } {
+                    break;
+                }
+                amount.push(chars.next().unwrap());
+            }
+            // println!("Amount: {amount}");
+            loop {
+                if match chars.peek() {
+                    None => true,
+                    Some(char) => char.is_numeric(),
+                } {
+                    break;
+                }
+                chars.next();
+            }
+            let mut origin = String::new();
+            loop {
+                if match chars.peek() {
+                    None => true,
+                    Some(char) => !char.is_numeric(),
+                } {
+                    break;
+                }
+                origin.push(chars.next().unwrap());
+            }
+            loop {
+                if match chars.peek() {
+                    None => true,
+                    Some(char) => char.is_numeric(),
+                } {
+                    break;
+                }
+                chars.next();
+            }
+            let mut destination = String::new();
+            loop {
+                if match chars.peek() {
+                    None => true,
+                    Some(char) => !char.is_numeric(),
+                } {
+                    break;
+                }
+                destination.push(chars.next().unwrap());
+            }
+
+            Instruction {
+                origin: origin.parse().expect("Non-numeric input encountered"),
+                destination: destination.parse().expect("Non-numeric input encountered"),
+                amount: amount.parse().expect("Non-numeric input encountered"),
+            }
+        })
+        .collect();
+
+    ChallengeInput {
+        initial_state,
+        instructions,
+    }
+}
+
+pub fn main() {
+    let input = parse_input(INPUT);
+    part_1(input.clone());
+    part_2(input);
+}

rust/src/day05/part_1.rs

@@ -0,0 +1,40 @@
+pub(crate) fn part_1(input: crate::ChallengeInput) -> String {
+    let mut state = input.initial_state.clone();
+
+    for crate::Instruction {
+        origin,
+        destination,
+        amount,
+    } in input.instructions
+    {
+        let length = state[origin - 1].len();
+        let (new_state, moved) = state[origin - 1].split_at(length - amount);
+        let new_state = new_state.to_vec();
+        let mut moved = moved.to_vec();
+        moved.reverse();
+
+        state[origin - 1] = new_state;
+        state[destination - 1].append(&mut moved);
+    }
+
+    state
+        .iter()
+        .filter(|stack| !stack.is_empty())
+        .map(|stack| stack.last().unwrap())
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    const SAMPLE_INPUT: &str = include_str!("sample_input.txt");
+
+    #[test]
+    fn test_with_solution() {
+        assert_eq!(super::part_1(crate::parse_input(crate::INPUT)), "RTGWZTHLD");
+    }
+
+    #[test]
+    fn test_with_sample_solution() {
+        assert_eq!(super::part_1(crate::parse_input(SAMPLE_INPUT)), "CMZ");
+    }
+}

rust/src/day05/part_2.rs

@@ -0,0 +1,40 @@
+pub(crate) fn part_2(input: crate::ChallengeInput) -> String {
+    let mut state = input.initial_state.clone();
+
+    for crate::Instruction {
+        origin,
+        destination,
+        amount,
+    } in input.instructions
+    {
+        let length = state[origin - 1].len();
+        let (new_state, moved) = state[origin - 1].split_at(length - amount);
+        let new_state = new_state.to_vec();
+        let mut moved = moved.to_vec();
+        // moved.reverse();
+
+        state[origin - 1] = new_state;
+        state[destination - 1].append(&mut moved);
+    }
+
+    state
+        .iter()
+        .filter(|stack| !stack.is_empty())
+        .map(|stack| stack.last().unwrap())
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    const SAMPLE_INPUT: &str = include_str!("sample_input.txt");
+
+    #[test]
+    fn test_with_solution() {
+        assert_eq!(super::part_2(crate::parse_input(crate::INPUT)), "STHGRZZFR");
+    }
+
+    #[test]
+    fn test_with_sample_solution() {
+        assert_eq!(super::part_2(crate::parse_input(SAMPLE_INPUT)), "MCD");
+    }
+}

rust/src/day05/sample_input.txt

@@ -0,0 +1,9 @@
+    [D]    
+[N] [C]    
+[Z] [M] [P]
+ 1   2   3 
+
+move 1 from 2 to 1
+move 3 from 1 to 3
+move 2 from 2 to 1
+move 1 from 1 to 2