From 0000039083a78b24c419aba16090c76a6c31c4e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matej=20Jane=C5=BEi=C4=8D?= <janezic.mj@gmail.com>
Date: Wed, 14 Dec 2022 09:59:43 +0100
Subject: [PATCH] solution: cleanup day23

---
 src/bin/23.rs          | 125 +++++++++++++++++++++++++++++++++++++++++
 src/test_inputs/23.txt |   8 +++
 2 files changed, 133 insertions(+)
 create mode 100644 src/bin/23.rs
 create mode 100644 src/test_inputs/23.txt

diff --git a/src/bin/23.rs b/src/bin/23.rs
new file mode 100644
index 000000000..911794e
--- /dev/null
+++ b/src/bin/23.rs
@@ -0,0 +1,125 @@
+use itertools::Itertools;
+use Instruction::*;
+enum Register {
+    A,
+    B,
+}
+
+impl From<&str> for Register {
+    fn from(value: &str) -> Self {
+        match value {
+            "a" => Register::A,
+            "b" => Register::B,
+            _ => unreachable!(),
+        }
+    }
+}
+
+enum Instruction {
+    Half(Register),
+    Triple(Register),
+    Increment(Register),
+    JumpOffset(i32),
+    JumpEven(Register, i32),
+    JumpOne(Register, i32),
+}
+
+impl From<&str> for Instruction {
+    fn from(value: &str) -> Self {
+        match value.split_once(' ').unwrap() {
+            ("hlf", x) => Half(Register::from(x)),
+            ("tpl", x) => Triple(Register::from(x)),
+            ("inc", x) => Increment(Register::from(x)),
+            ("jmp", x) => JumpOffset(x.parse().unwrap()),
+            ("jie", x) => {
+                let (reg, offset) = x.split_once(", ").unwrap();
+                JumpEven(Register::from(reg), offset.parse().unwrap())
+            }
+            ("jio", x) => {
+                let (reg, offset) = x.split_once(", ").unwrap();
+                JumpOne(Register::from(reg), offset.parse().unwrap())
+            }
+            _ => unreachable!(),
+        }
+    }
+}
+
+fn run_instructions(input: &str, mut a: u32, mut b: u32) -> Option<u32> {
+    let instructions = input.split('\n').map(Instruction::from).collect_vec();
+    let mut index = 0;
+    while let Some(instruction) = instructions.get(index) {
+        match instruction {
+            Half(x) => {
+                match x {
+                    Register::A => a /= 2,
+                    Register::B => b /= 2,
+                }
+                index += 1;
+            }
+            Triple(x) => {
+                match x {
+                    Register::A => a *= 3,
+                    Register::B => b *= 3,
+                }
+                index += 1;
+            }
+            Increment(x) => {
+                match x {
+                    Register::A => a += 1,
+                    Register::B => b += 1,
+                }
+                index += 1;
+            }
+            JumpOffset(x) => index += *x as usize,
+            JumpEven(r, x) => {
+                let reg = match r {
+                    Register::A => a,
+                    Register::B => b,
+                };
+                if reg % 2 == 0 {
+                    index += *x as usize
+                } else {
+                    index += 1;
+                }
+            }
+            JumpOne(r, x) => {
+                let reg = match r {
+                    Register::A => a,
+                    Register::B => b,
+                };
+                if reg == 1 {
+                    index += *x as usize
+                } else {
+                    index += 1;
+                }
+            }
+        }
+    }
+    Some(b)
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    run_instructions(input, 0, 0)
+}
+pub fn part_two(input: &str) -> Option<u32> {
+    run_instructions(input, 1, 0)
+}
+fn main() {
+    let input = &aoc::read_file("inputs", 23);
+    aoc::solve!(1, part_one, input);
+    aoc::solve!(2, part_two, input);
+}
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_part_one() {
+        let input = aoc::read_file("test_inputs", 23);
+        assert_eq!(part_one(&input.trim()), Some(2));
+    }
+    #[test]
+    fn test_part_two() {
+        let input = aoc::read_file("test_inputs", 23);
+        assert_eq!(part_two(&input.trim()), Some(2));
+    }
+}
diff --git a/src/test_inputs/23.txt b/src/test_inputs/23.txt
new file mode 100644
index 000000000..38c53a1
--- /dev/null
+++ b/src/test_inputs/23.txt
@@ -0,0 +1,8 @@
+inc a
+jio a, +2
+tpl a
+inc a
+inc b
+jio b, +2
+tpl b
+inc b