2022 day10/rust: cleanup

2022/day10/rust/src/main.rs

@@ -2,11 +2,10 @@
 
 use std::{
     io::{stdin, Read},
+    iter,
     str::FromStr,
 };
 
-use aoc::*;
-
 enum Instruction {
     Noop,
     Addx(i32),
@@ -17,10 +16,10 @@ impl FromStr for Instruction {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut args = s.split_whitespace();
-        match args.next().unwrap() {
+        match args.next().ok_or(())? {
             "noop" => Ok(Self::Noop),
             "addx" => {
-                let i = args.next().unwrap().parse().unwrap();
+                let i = args.next().ok_or(())?.parse().map_err(|_| ())?;
                 Ok(Self::Addx(i))
             }
             _ => Err(()),
@@ -43,27 +42,25 @@ fn main() {
             *acc += i;
             Some(*acc)
         });
-    let values = [1, 1]
-        .into_iter()
+    let values = iter::once(1)
         .chain(values)
         .enumerate()
-        .map(|(i, x)| (i32::try_from(i).unwrap(), x));
+        .map(|(i, x)| (i32::try_from(i).unwrap() + 1, x));
+
     let sum: i32 = values
         .clone()
-        .skip(20)
+        .skip(20 - 1)
         .step_by(40)
         .map(|(i, x)| i * x)
         .sum();
+    println!("{:?}", sum);
 
     let crt: Vec<_> = values
-        .skip(1)
-        .map(|(i, x)| ((i - 1) % 40 - x).abs() < 2)
+        .map(|(i, x)| ((i - 1) % 40).abs_diff(x) < 2)
         .map(|x| if x { '#' } else { '.' })
         .collect();
-    let (_, crt) = crt.split_last().unwrap();
 
-    println!("{:?}", sum);
-    for line in crt.chunks(40) {
+    for line in crt.chunks_exact(40) {
         println!("{}", line.iter().collect::<String>());
     }
 }