Day 10. I'm a bit behind. CA trip got in the way

day10/src/main.rs

@@ -0,0 +1,67 @@
+#[derive(Debug)]
+enum Instruction {
+    Noop,
+    AddX(i32),
+}
+
+fn main() {
+    let contents = std::fs::read_to_string("data.txt").expect("Failed to read file");
+    let ops = contents.lines().map(parse).collect::<Vec<Instruction>>();
+
+    let strength = run(&ops);
+    println!("total signal strength {:?}", strength);
+}
+
+fn parse(line: &str) -> Instruction {
+    let parts = line.split(" ").collect::<Vec<&str>>();
+    match parts[0] {
+        "noop" => Instruction::Noop,
+        _ => Instruction::AddX(parts[1].parse().unwrap()),
+    }
+}
+
+fn run(ops: &Vec<Instruction>) -> i32 {
+    let mut x: i32 = 1;
+    let mut cycle = 1;
+    let mut to_add = None;
+    let mut op_idx = 0;
+    let mut strength = 0;
+
+    while op_idx < ops.len() {
+        let pixel = cycle % 40;
+        let diff = (x + 1 - pixel).abs();
+        if diff.abs() <= 1 {
+            print!("#");
+        } else {
+            print!(" ");
+        }
+
+        match to_add {
+            None => {
+                match ops[op_idx] {
+                    Instruction::Noop => (),
+                    Instruction::AddX(v) => {
+                        to_add = Some(v);
+                    }
+                }
+                op_idx += 1;
+            }
+            Some(v) => {
+                x += v;
+                to_add = None;
+            }
+        }
+
+        if (cycle + 20) % 40 == 0 {
+            strength += x * cycle;
+        }
+
+        if cycle % 40 == 0 {
+            println!();
+        }
+
+        cycle += 1;
+    }
+
+    strength
+}