day 5 part 1. Mostly parsing, quite unfun

src/bin/05.rs

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+use regex::Regex;
+
+#[derive(Debug)]
+pub struct Instruction {
+    from: usize,
+    to: usize,
+    amount: usize
+}
+
+pub fn parse_instructions(input: &str) -> Vec<Instruction> {
+    let instructionre = Regex::new(r"move (\d+) from (\d+) to (\d+)").unwrap();
+    let mut instructions = Vec::new();
+    for l in input.lines() {
+        let matches = instructionre.captures(l).unwrap();
+        let amount:usize = matches[1].parse().unwrap();
+        let from:usize = matches[2].parse().unwrap();
+        let to:usize = matches[3].parse().unwrap();
+        instructions.insert(instructions.len(),Instruction{from, to,amount});
+    }
+    instructions
+}
+
+pub fn parse_stacks(input: &str) -> Vec<Vec<char>> {
+    let mut stacks: Vec<Vec<char>> = Vec::new();
+    for l in input.lines() {
+        let lchars: Vec<char> = l.chars().collect();
+
+        if !(l.starts_with(" 1")) { // skip lines with only numbers
+            for i in 0..(lchars.len()/4)+1 {
+                if stacks.len() <= i {
+                        stacks.insert(i,Vec::new());
+                    }
+                if lchars[(i*4)+1] != ' ' {
+                    stacks[i].insert(0,lchars[(i*4)+1]);
+                }
+            }
+        }
+    }
+    stacks
+
+}
+
+pub fn part_one(input: &str) -> Option<String> {
+    let parts: Vec<&str> = input.split("\n\n").collect();
+    let mut stacks = parse_stacks(parts[0]);
+    let instructions = parse_instructions(parts[1]);
+    for i in instructions {
+        for _ in 0..(i.amount) {
+            let x = stacks[i.from-1].pop().unwrap();
+            stacks[i.to-1].push(x);
+        }
+    }
+    Some(stacks.iter()
+    .map(| x | x[x.len()-1].to_string()) // stringify top element of every stack
+    .reduce(| x, y | x + &y).unwrap()) // and merge into one big string
+}
+
+pub fn part_two(input: &str) -> Option<String> {
+    let _ = input;
+
+    None
+}
+
+fn main() {
+    let input = &advent_of_code::read_file("inputs", 5);
+    advent_of_code::solve!(1, part_one, input);
+    advent_of_code::solve!(2, part_two, input);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let input = advent_of_code::read_file("examples", 5);
+        assert_eq!(part_one(&input), Some("CMZ".to_string()));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let input = advent_of_code::read_file("examples", 5);
+        assert_eq!(part_two(&input), None);
+    }
+}

src/examples/05.txt

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+    [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