Start day 14 - Docking Data

14-docking_data/src/main.rs

@@ -0,0 +1,94 @@
+use std::{collections::HashMap, convert::{TryFrom}, str::FromStr};
+
+#[derive(Debug, PartialEq, thiserror::Error)]
+enum DDError {
+    #[error("Mask Error: {0}")]
+    MaskError(&'static  str)
+}
+#[derive(Debug, PartialEq)]
+enum MaskItem {
+    Zero,
+    One,
+    X,
+}
+
+impl TryFrom<char> for MaskItem {
+    type Error = DDError;
+
+    fn try_from(c: char) -> Result<Self, Self::Error> {
+        Ok(match c {
+            '0' => MaskItem::Zero,
+            '1' => MaskItem::One,
+            'X' => MaskItem::X,
+            _ => return Err(DDError::MaskError("Invalid Mask character"))
+        })
+    }
+}
+
+type Mem = HashMap<i64, i64>;
+struct Mask {
+    set: i64,
+    reset: i64,
+}
+
+impl Default for Mask {
+    fn default() -> Self {
+        Mask {
+            set: 0,
+            reset: 0, 
+        }
+    }
+}
+
+impl FromStr for Mask {
+    type Err = DDError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let (mut set, mut reset) = (0, 0);
+        for (shift, c) in s.chars().rev().enumerate() {
+            match MaskItem::try_from(c)? {
+                MaskItem::Zero => reset |= 1 << shift,
+                MaskItem::One => set |= 1<<shift,
+                MaskItem::X => {}
+            };
+        }
+        Ok(Mask {set,reset})
+    }
+} 
+
+impl Mask {
+    fn apply(&self, n: i64) -> i64 {
+        (n | self.set) & !self.reset
+    }
+}
+
+fn main() {
+    println!("Hello, world!");
+}
+
+#[cfg(test)]
+mod tests {
+    use std::convert::TryInto;
+
+    use super::*;
+
+    #[test]
+    fn test_char() {
+        assert_eq!(TryInto::<MaskItem>::try_into('X').unwrap(), MaskItem::X);
+        assert_eq!(TryInto::<MaskItem>::try_into('1').unwrap(), MaskItem::One);
+        assert_eq!(TryInto::<MaskItem>::try_into('0').unwrap(), MaskItem::Zero);
+        assert_eq!(TryInto::<MaskItem>::try_into('d').is_err(), true);
+    }
+
+    #[test]
+    fn test_mask() {
+        let mask = Mask {
+            set: 12,   // 0b001100
+            reset: 19, // 0b010011
+        };
+        // 31 = 0b011111
+        assert_eq!(mask.apply(31), 12);
+        // 32 = 0b100000
+        assert_eq!(mask.apply(32), 44);
+    }
+}