Tidy

Author: maneatingape

src/year2024/day25.rs

@@ -1,41 +1,32 @@
 //! # Code Chronicle
+const MASK: u64 = 0b011111_011111_011111_011111_011111_011111_011111;
+
 pub fn parse(input: &str) -> &str {
     input
 }
 
 pub fn part1(input: &str) -> u32 {
-    let mut iter = input.bytes();
+    let mut iter = input.bytes().map(|b| (b & 1) as u64);
     let mut locks = Vec::with_capacity(250);
     let mut keys = Vec::with_capacity(250);
     let mut result = 0;
 
-    loop {
-        let mut bits = 0;
-
-        for _ in 0..41 {
-            let b = iter.next().unwrap();
-            bits = (bits << 1) | (b & 1) as u64;
-        }
-
-        bits &= 0b011111_011111_011111_011111_011111_011111_011111;
+    while let Some(first) = iter.next() {
+        let bits = (0..40).fold(first, |bits, _| (bits << 1) | iter.next().unwrap());
 
-        if bits & 0b011111_000000_000000_000000_000000_000000_000000 != 0 {
-            locks.push(bits);
+        if bits & 1 == 0 {
+            locks.push(bits & MASK);
         } else {
-            keys.push(bits);
+            keys.push(bits & MASK);
         }
 
         iter.next();
-        if iter.next().is_none() {
-            break;
-        }
+        iter.next();
     }
 
     for lock in &locks {
         for key in &keys {
-            if lock & key == 0 {
-                result += 1;
-            }
+            result += (lock & key == 0) as u32;
         }
     }