y2015d23 refreshingly easy

y2015/src/bin/d23.rs

@@ -10,11 +10,11 @@ fn main() {
 fn part1() {
     let root = env!("CARGO_MANIFEST_DIR");
     let content = fs::read_to_string(format!("{root}/resources/23_input.txt")).unwrap();
-    println!("{}", d23::process_part1(&content));
+    println!("{:?}", d23::process_part1(&content));
 }
 
 fn part2() {
     let root = env!("CARGO_MANIFEST_DIR");
     let content = fs::read_to_string(format!("{root}/resources/23_input.txt")).unwrap();
-    println!("{}", d23::process_part2(&content));
+    println!("{:?}", d23::process_part2(&content));
 }

y2015/src/days/d23.rs

@@ -1,25 +1,135 @@
-enum Instruction {
+use core::panic;
-    Half,
-    Triple,
-    Increment,
-    Jump,
-    JumpEven,
-    JumpOne,
-}
 
-pub fn process_part1(input: &str) -> i32 {
+pub fn process_part1(input: &str) -> (i32, i32) {
     let mut a = 0;
     let mut b = 0;
-    let lines = input
+    let instructions = input
         .lines()
         .map(|line| line.to_string())
         .collect::<Vec<String>>();
-    let mut idx = 0;
+    let mut idx: i32 = 0;
-    b
+    loop {
+        if let Some(instruction) = instructions.get(idx as usize) {
+            let (instruction_name, instruction_action) = instruction.split_once(" ").unwrap();
+            match instruction_name {
+                "hlf" => {
+                    if instruction_action == "a" {
+                        a /= 2;
+                    } else if instruction_action == "b" {
+                        b /= 2;
+                    }
+                    idx += 1;
+                }
+                "tpl" => {
+                    if instruction_action == "a" {
+                        a *= 3;
+                    } else if instruction_action == "b" {
+                        b *= 3;
+                    }
+                    idx += 1;
+                }
+                "inc" => {
+                    if instruction_action == "a" {
+                        a += 1;
+                    } else if instruction_action == "b" {
+                        b += 1;
+                    }
+                    idx += 1;
+                }
+                "jmp" => {
+                    let offset = instruction_action.parse::<i32>().unwrap();
+                    idx += offset;
+                }
+                "jie" => {
+                    let (reg, offset) = instruction_action.split_once(", ").unwrap();
+                    let offset: i32 = offset.parse().unwrap();
+                    if (reg == "a" && a % 2 == 0) || (reg == "b" && b % 2 == 0) {
+                        idx += offset;
+                    } else {
+                        idx += 1;
+                    }
+                }
+                "jio" => {
+                    let (reg, offset) = instruction_action.split_once(", ").unwrap();
+                    let offset: i32 = offset.parse().unwrap();
+                    if (reg == "a" && a == 1) || (reg == "b" && b == 1) {
+                        idx += offset;
+                    } else {
+                        idx += 1;
+                    }
+                }
+                _ => panic!("Unknown instruction {instruction_name}"),
+            }
+        } else {
+            return (a, b);
+        }
+    }
 }
 
-pub fn process_part2(input: &str) -> i32 {
+pub fn process_part2(input: &str) -> (i32, i32) {
-    0
+    let mut a = 1;
+    let mut b = 0;
+    let instructions = input
+        .lines()
+        .map(|line| line.to_string())
+        .collect::<Vec<String>>();
+    let mut idx: i32 = 0;
+    loop {
+        if let Some(instruction) = instructions.get(idx as usize) {
+            let (instruction_name, instruction_action) = instruction.split_once(" ").unwrap();
+            match instruction_name {
+                "hlf" => {
+                    if instruction_action == "a" {
+                        a /= 2;
+                    } else if instruction_action == "b" {
+                        b /= 2;
+                    }
+                    idx += 1;
+                }
+                "tpl" => {
+                    if instruction_action == "a" {
+                        a *= 3;
+                    } else if instruction_action == "b" {
+                        b *= 3;
+                    }
+                    idx += 1;
+                }
+                "inc" => {
+                    if instruction_action == "a" {
+                        a += 1;
+                    } else if instruction_action == "b" {
+                        b += 1;
+                    }
+                    idx += 1;
+                }
+                "jmp" => {
+                    let offset = instruction_action.parse::<i32>().unwrap();
+                    idx += offset;
+                }
+                "jie" => {
+                    let (reg, offset) = instruction_action.split_once(", ").unwrap();
+                    let offset: i32 = offset.parse().unwrap();
+                    if (reg == "a" && a % 2 == 0) || (reg == "b" && b % 2 == 0) {
+                        idx += offset;
+                    } else {
+                        idx += 1;
+                    }
+                }
+                "jio" => {
+                    let (reg, offset) = instruction_action.split_once(", ").unwrap();
+                    let offset: i32 = offset.parse().unwrap();
+                    if (reg == "a" && a == 1) || (reg == "b" && b == 1) {
+                        idx += offset;
+                    } else {
+                        idx += 1;
+                    }
+                }
+                _ => panic!("Unknown instruction {instruction_name}"),
+            }
+        } else {
+            return (a, b);
+        }
+    }
 }
 
 #[cfg(test)]
@@ -34,12 +144,12 @@ inc a";
     #[test]
     fn part1() {
         let result = process_part1(INPUT);
-        assert_eq!(result, 2);
+        assert_eq!(result.0, 2);
     }
 
     #[test]
     fn part2() {
         let result = process_part2(INPUT);
-        assert_eq!(result, 0);
+        assert_eq!(result.0, 7);
     }
 }