add day 1 and 2

2026-06-26 22:49:45 +02:00
parent 3cb098048d
commit 1d54ac6752
10 changed files with 304 additions and 0 deletions
@@ -0,0 +1,137 @@
+use std::collections::HashSet;
+
+fn main() {
+    let data: Vec<_> =
+        Instruction::parse(std::fs::read_to_string("input.txt").unwrap().trim()).collect();
+
+    part1(&data);
+    part2(&data);
+}
+
+fn part2(data: &[Instruction]) {
+    let mut visited = HashSet::new();
+    let mut direction = Direction::North;
+
+    let mut x: i32 = 0;
+    let mut y: i32 = 0;
+
+    'outer: for i in data {
+        direction = i.change(direction);
+        match direction {
+            Direction::North => {
+                for _ in 0..i.value() {
+                    y += 1;
+                    if visited.contains(&(x, y)) {
+                        break 'outer;
+                    }
+                    visited.insert((x, y));
+                }
+            }
+            Direction::East => {
+                for _ in 0..i.value() {
+                    x += 1;
+                    if visited.contains(&(x, y)) {
+                        break 'outer;
+                    }
+                    visited.insert((x, y));
+                }
+            }
+            Direction::South => {
+                for _ in 0..i.value() {
+                    y -= 1;
+                    if visited.contains(&(x, y)) {
+                        break 'outer;
+                    }
+                    visited.insert((x, y));
+                }
+            }
+            Direction::West => {
+                for _ in 0..i.value() {
+                    x -= 1;
+                    if visited.contains(&(x, y)) {
+                        break 'outer;
+                    }
+                    visited.insert((x, y));
+                }
+            }
+        }
+    }
+
+    println!("{}", x.abs() + y.abs());
+}
+
+fn part1(data: &[Instruction]) {
+    let mut direction = Direction::North;
+
+    let mut x = 0;
+    let mut y = 0;
+
+    for i in data {
+        direction = i.change(direction);
+        match direction {
+            Direction::North => y += i.value() as i32,
+            Direction::East => x += i.value() as i32,
+            Direction::South => y -= i.value() as i32,
+            Direction::West => x -= i.value() as i32,
+        }
+    }
+
+    println!("{}", x.abs() + y.abs());
+}
+
+#[derive(Debug, PartialEq)]
+enum Instruction {
+    L(usize),
+    R(usize),
+}
+
+#[derive(Debug)]
+enum Direction {
+    North,
+    East,
+    South,
+    West,
+}
+
+impl Instruction {
+    fn change(&self, d: Direction) -> Direction {
+        if let Instruction::R(_) = self {
+            match d {
+                Direction::North => Direction::East,
+                Direction::East => Direction::South,
+                Direction::South => Direction::West,
+                Direction::West => Direction::North,
+            }
+        } else {
+            match d {
+                Direction::North => Direction::West,
+                Direction::East => Direction::North,
+                Direction::South => Direction::East,
+                Direction::West => Direction::South,
+            }
+        }
+    }
+
+    fn value(&self) -> usize {
+        match self {
+            Instruction::L(val) => *val,
+            Instruction::R(val) => *val,
+        }
+    }
+}
+
+impl Instruction {
+    fn parse(s: &str) -> impl Iterator<Item = Self> {
+        let mut result = vec![];
+        for item in s.split(", ") {
+            let amount = item.chars().skip(1).collect::<String>().parse().unwrap();
+            let this = if item.contains('L') {
+                Instruction::L(amount)
+            } else {
+                Instruction::R(amount)
+            };
+            result.push(this);
+        }
+        result.into_iter()
+    }
+}