Tidy

1 files changed, 36 insertions, 84 deletions

diff --git a/day1/src/main.rs b/day1/src/main.rs
index 2058021..50ab8e1 100644
--- a/day1/src/main.rs
+++ b/day1/src/main.rs
@@ -39,51 +39,28 @@ struct Dial(u8);
 struct RotateResult(u32, Dial);
 
 impl Dial {
-    fn new() -> Self {
-        Self(50)
-    }
-
     fn rotate(self, rot: &Rotation) -> RotateResult {
-        match rot {
-            Rotation::Left(n) => self.rotate_left(*n),
-            Rotation::Right(n) => self.rotate_right(*n),
-        }
-    }
-
-    fn rotate_left(self, n: u32) -> RotateResult {
         let pos = self.0 as u32;
 
-        if pos != 0 && n >= pos {
-            let quot = n.div_ceil(100);
-            RotateResult(quot, self - n)
-        } else {
-            RotateResult(0, self - n)
-        }
-    }
-
-    fn rotate_right(self, n: u32) -> RotateResult {
-        let pos = self.0 as u32;
-
-        if n + pos >= 100 {
-            let quot = n.div_ceil(100);
-            RotateResult(quot, self + n)
-        } else {
-            RotateResult(0, self + n)
-        }
-    }
-
-    fn rotate_all(self, rotations: &[Rotation]) -> RotateResult {
-        let mut dial = Dial::from(50);
-        let mut zeros_total = 0;
-
-        for rot in rotations {
-            let RotateResult(zeros, new_dial) = dial.rotate(rot);
-            zeros_total += zeros;
-            dial = new_dial;
-            println!("{:?}, dial: {}, zeros: {}", rot, dial.0, zeros);
+        match rot {
+            Rotation::Left(n) => {
+                if pos != 0 && *n >= pos {
+                    let quot = n.div_ceil(100);
+                    RotateResult(quot, self - *n)
+                } else {
+                    RotateResult(0, self - *n)
+                }
+            }
+
+            Rotation::Right(n) => {
+                if n + pos >= 100 {
+                    let quot = n.div_ceil(100);
+                    RotateResult(quot, self + *n)
+                } else {
+                    RotateResult(0, self + *n)
+                }
+            }
         }
-
-        RotateResult(zeros_total, dial)
     }
 }
 
@@ -119,37 +96,9 @@ impl PartialEq<u8> for Dial {
     }
 }
 
-fn part1(rotations: &[Rotation]) -> RotateResult {
-    let mut dial = Dial::new();
-    let mut zeros = 0;
-
-    for rot in rotations {
-        match rot {
-            Rotation::Left(n) => dial = dial - *n,
-            Rotation::Right(n) => dial = dial + *n,
-        }
-
-        if dial == 0 {
-            zeros = zeros + 1;
-        }
-    }
-
-    RotateResult(zeros, dial)
-}
-
 fn main() -> anyhow::Result<()> {
-    let usage_err = || anyhow!("usage: day1 PART INPUT");
-
     let mut args = env::args();
-
-    let part: u8 = args
-        .nth(1)
-        .ok_or_else(usage_err)?
-        .parse()
-        .map_err(|_| usage_err())?;
-
-    let input_path = args.next().ok_or_else(usage_err)?;
-
+    let input_path = args.nth(1).ok_or_else(|| anyhow!("usage: day1 INPUT"))?;
     let input = fs::read_to_string(input_path)?;
 
     let rotations: Vec<Rotation> = input
@@ -157,22 +106,25 @@ fn main() -> anyhow::Result<()> {
         .map(|s| s.parse().map_err(|_| anyhow!("bad rotation: {}", s)))
         .collect::<anyhow::Result<_>>()?;
 
-    match part {
-        1 => {
-            let RotateResult(zeros, _) = part1(&rotations);
-            println!("Result: {}", zeros);
-            Ok(())
-        }
+    let mut dial = Dial::from(50);
+    let mut exact_zeros = 0;
+    let mut total_zeros = 0;
 
-        2 => {
-            let dial = Dial::from(50);
-            let RotateResult(zeros, _) = dial.rotate_all(&rotations);
-            println!("Result: {}", zeros);
-            Ok(())
+    for rot in &rotations {
+        let RotateResult(zeros, new_dial) = dial.rotate(rot);
+
+        if new_dial == 0 {
+            exact_zeros += 1;
         }
 
-        _ => Err(usage_err()),
+        total_zeros += zeros;
+        dial = new_dial;
     }
+
+    println!("Password: {}", exact_zeros);
+    println!("Password (method 0x434C49434B): {}", total_zeros);
+
+    Ok(())
 }
 
 #[cfg(test)]
@@ -196,7 +148,7 @@ mod tests {
 
     #[test]
     fn dial_ops() {
-        let dial = Dial::new();
+        let dial = Dial::from(50);
 
         assert_eq!(dial + 1, 51);
         assert_eq!(dial + 50, 0);
@@ -219,7 +171,7 @@ mod tests {
 
     #[test]
     fn dial_rotate() {
-        let mut dial = Dial::new();
+        let mut dial = Dial::from(50);
 
         let rotations = vec![
             // Example data