day 23 part 1

src/day23.rs

@@ -1,18 +1,84 @@
 use aoc_runner_derive::{aoc, aoc_generator};
 
-type Input = ();
+type Input = String;
 
-#[aoc_generator(day22)]
+#[aoc_generator(day23)]
 fn parse(input: &str) -> Input {
-    todo!()
+    input.to_string()
 }
 
-#[aoc(day22, part1)]
-fn part1(_: &Input) -> usize {
-    0
+#[aoc(day23, part1)]
+fn part1(input: &Input) -> usize {
+    let mut a = 0;
+    let mut b = 0;
+    let mut ip: i32 = 0;
+
+    let mem = input.lines().collect::<Vec<_>>();
+
+    while let Some(line) = mem.get(ip as usize) {
+        let (lhs, rhs) = line.split_once(" ").unwrap();
+        match lhs {
+            "hlf" => {
+                match rhs {
+                    "a" => a /= 2,
+                    "b" => b /= 2,
+                    _ => panic!("unknown register"),
+                };
+            }
+            "tpl" => {
+                match rhs {
+                    "a" => a *= 3,
+                    "b" => b *= 3,
+                    _ => panic!("unknown register"),
+                };
+            }
+            "inc" => {
+                match rhs {
+                    "a" => a += 1,
+                    "b" => b += 1,
+                    _ => panic!("unknown register"),
+                };
+            }
+            "jmp" => {
+                let offset = parse_offset(rhs);
+                ip += offset - 1;
+            }
+            "jie" => {
+                let (r, o) = rhs.split_once(", ").unwrap();
+                let offset = parse_offset(o);
+                let jump = match r {
+                    "a" => a % 2 == 0,
+                    "b" => b % 2 == 0,
+                    _ => panic!(),
+                };
+                if jump {
+                    ip += offset - 1;
+                }
+            }
+            "jio" => {
+                let (r, o) = rhs.split_once(", ").unwrap();
+                let offset = parse_offset(o);
+                let jump = match r {
+                    "a" => a == 1,
+                    "b" => b == 1,
+                    _ => panic!(),
+                };
+                if jump {
+                    ip += offset - 1;
+                }
+            }
+            _ => panic!("unknown instruction"),
+        }
+        ip += 1;
+    }
+    b
 }
 
-#[aoc(day22, part2)]
+fn parse_offset(input: &str) -> i32 {
+    input.parse().unwrap()
+}
+
+#[aoc(day23, part2)]
 fn part2(_: &Input) -> usize {
     0
 }