day 10 done

day10/src/main.rs

@@ -0,0 +1,46 @@
+use std::fs::File;
+use std::io::{prelude::*, BufReader};
+use std::str;
+
+fn main() -> std::io::Result<()> {
+    //Read in file
+    let file = File::open("input")?;
+    let reader = BufReader::new(file);
+
+    let mut part1: Vec<i32> = Vec::new();
+    let mut part2 = [[b'.'; 40]; 6];
+    let mut x_reg = 1;
+    let mut pc = 0;
+
+    reader.lines().for_each(|line| {
+        let line = line.unwrap();
+        let op = match line.split(' ').collect::<Vec<_>>()[..] {
+            ["addx", x] => Some(x.parse::<i32>().unwrap()),
+            ["noop"] => None,
+            _ => panic!("invalid command: {}", line),
+        };
+        let steps = if op.is_some() { 2 } else { 1 };
+        for i in 0..steps {
+            let row = pc / 40;
+            let col = pc % 40;
+            if col - 1 == x_reg || col == x_reg || col + 1 == x_reg {
+                part2[row as usize][col as usize] = b'#';
+            }
+            pc += 1;
+            if pc < 221 && (pc - 20) % 40 == 0 {
+                part1.push(pc * x_reg);
+            }
+            if i == steps - 1 {
+                if let Some(x) = op {
+                    x_reg += x;
+                }
+            }
+        }
+    });
+
+    println!("Part 1: {}", part1.iter().sum::<i32>());
+    for row in part2 {
+        println!("Part 2: {}", str::from_utf8(&row).unwrap());
+    }
+    Ok(())
+}