From dbb5a4e5711fba371fbb011356bcd8a28cc963e4 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Tue, 8 Jul 2025 17:10:53 +0200
Subject: Day 22 2022

---
 2022/22/common.rs | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 2022/22/common.rs

(limited to '2022/22/common.rs')

diff --git a/2022/22/common.rs b/2022/22/common.rs
new file mode 100644
index 0000000..881513c
--- /dev/null
+++ b/2022/22/common.rs
@@ -0,0 +1,111 @@
+use std::cmp::*;
+
+#[derive(PartialEq, Copy, Clone, Debug)]
+pub enum Tile { Walk, Wall, Skip }
+
+#[allow(dead_code)]
+impl Tile {
+    pub fn from_byte(b: u8) -> Tile {
+        match b {
+            b'.' => Tile::Walk,
+            b'#' => Tile::Wall,
+            b' ' => Tile::Skip,
+            _ => panic!("not a valid tile {}", b)
+        }
+    }
+
+    pub fn to_char(&self) -> char {
+        match self {
+            Tile::Walk => '.',
+            Tile::Wall => '#',
+            Tile::Skip => ' '
+        }
+    }
+}
+
+#[derive(PartialEq, Copy, Clone, Debug)]
+pub enum Direction { Up, Down, Right, Left }
+
+#[allow(dead_code)]
+impl Direction {
+    pub fn from_char(c: char) -> Direction {
+        match c {
+            'U' => Direction::Up,
+            'D' => Direction::Down,
+            'R' => Direction::Right,
+            'L' => Direction::Left,
+            _ => panic!("invalid char for direction")
+        }
+    }
+
+    pub fn turn(&self, t: Direction) -> Direction {
+        match t {
+            Direction::Right => match self {
+                Direction::Up => Direction::Right,
+                Direction::Right => Direction::Down,
+                Direction::Down => Direction::Left,
+                Direction::Left => Direction::Up
+            },
+            Direction::Left => match self {
+                Direction::Up => Direction::Left,
+                Direction::Left => Direction::Down,
+                Direction::Down => Direction::Right,
+                Direction::Right => Direction::Up
+            }
+            _ => panic!("cannot turn up or down")
+        }
+    }
+
+    pub fn step(&self) -> (i64, i64) {
+        match self {
+            Direction::Up => (-1, 0),
+            Direction::Down => (1, 0),
+            Direction::Right => (0, 1),
+            Direction::Left => (0, -1)
+        }
+    }
+
+    pub fn value(&self) -> usize {
+        match self {
+            Direction::Right => 0,
+            Direction::Down => 1,
+            Direction::Left => 2,
+            Direction::Up => 3
+        }
+    }
+
+    pub fn opposite(&self) -> Direction {
+        match self {
+            Direction::Right => Direction::Left,
+            Direction::Left => Direction::Right,
+            Direction::Up => Direction::Down,
+            Direction::Down => Direction::Up
+        }
+    }
+
+    pub fn is_positive(&self) -> bool {
+        *self == Direction::Down || *self == Direction::Right
+    }
+}
+
+pub fn read_instruction_line_from_stdin() -> (Vec<Direction>, Vec<usize>) {
+    let mut dir = vec![];
+    let mut step = vec![];
+    let mut line = String::new();
+    let _ = std::io::stdin().read_line(&mut line);
+    let mut i = 0;
+    while i < line.len()-1 {
+        match line.chars().nth(i).unwrap() {
+            '0'..='9' => {
+                let j = line[i..].find(|c: char| !c.is_digit(10)).unwrap() + i;
+                step.push(line[i..j].parse::<usize>().unwrap());
+                i = j;
+            },
+            c => {
+                dir.push(Direction::from_char(c));
+                i += 1;
+            }
+        }
+    }
+    (dir, step)
+}
-- 
cgit v1.3