From 1b9ea6972c94433c9bcde5551a5437a26671db2f Mon Sep 17 00:00:00 2001
From: Jeremy Kaplan <jdkaplan@metagram.net>
Date: Fri, 9 Dec 2022 21:55:07 -0800
Subject: [PATCH] 2022 Day 10

---
 2022/src/bin/day10.rs | 81 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 2022/src/bin/day10.rs

diff --git a/2022/src/bin/day10.rs b/2022/src/bin/day10.rs
new file mode 100644
index 0000000..3d7c108
--- /dev/null
+++ b/2022/src/bin/day10.rs
@@ -0,0 +1,81 @@
+const INPUT: &str = include_str!("../../input/day10.txt");
+
+fn main() {
+    let instructions = parse(INPUT);
+
+    let mut crt = Crt::new();
+
+    for i in instructions {
+        crt.run(i);
+    }
+
+    println!("Part 1: {}", crt.strength);
+    println!("{}", crt.image);
+}
+
+#[derive(Debug, Copy, Clone)]
+enum Instruction {
+    Noop,
+    Addx(i64),
+}
+
+fn parse(input: &str) -> Vec<Instruction> {
+    aoc::split_lines(input)
+        .iter()
+        .map(|line| {
+            let w = aoc::split_words(line);
+            match w[0] {
+                "noop" => Instruction::Noop,
+                "addx" => Instruction::Addx(w[1].parse().unwrap()),
+                other => panic!("{}", other),
+            }
+        })
+        .collect()
+}
+
+#[derive(Debug, Clone)]
+struct Crt {
+    cycle: usize,
+    x: i64,
+
+    strength: i64,
+    image: String,
+}
+
+impl Crt {
+    fn new() -> Self {
+        Self {
+            cycle: 0,
+            x: 1,
+
+            strength: 0,
+            image: String::new(),
+        }
+    }
+
+    fn run(&mut self, i: Instruction) {
+        let dxs = match i {
+            Instruction::Noop => vec![0],
+            Instruction::Addx(dx) => vec![0, dx],
+        };
+
+        for dx in dxs {
+            let scanx = (self.cycle as i64) % 40;
+            if scanx == 0 {
+                self.image += "\n";
+            }
+
+            self.cycle += 1;
+
+            let pixel = if (self.x - scanx).abs() < 2 { "#" } else { "." };
+            self.image += pixel;
+
+            let signal = (self.cycle as i64) * self.x;
+            if (self.cycle + 20) % 40 == 0 {
+                self.strength += signal;
+            }
+
+            self.x += dx;
+        }
+    }
+}