do day 2

2022/input/day_2_sample.txt

@@ -1,14 +1,3 @@
-1000
-2000
-3000
-
-4000
-
-5000
-6000
-
-7000
-8000
-9000
-
-10000
+A Y
+B X
+C Z

2022/src/day_2.rs

@@ -1,15 +1,72 @@
+use Shape::*;
+
+#[derive(Debug)]
+enum Shape {
+    Rock,
+    Paper,
+    Scissors,
+}
+impl Shape {
+    fn from_char(c: char) -> Self {
+        match c {
+            'A' | 'X' => Rock,
+            'B' | 'Y' => Paper,
+            'C' | 'Z' => Scissors,
+            _ => panic!("expected A, Y, B, X, C, or Z"),
+        }
+    }
+    fn as_int(&self) -> i32 {
+        match self {
+            Rock => 1,
+            Paper => 2,
+            Scissors => 3,
+        }
+    }
+    fn result(&self, other: &Self) -> i32 {
+        self.as_int()
+            + if self.as_int() == other.as_int() {
+                3
+            } else if std::cmp::max((self.as_int() + 1) % 4, 1) == other.as_int() {
+                0
+            } else {
+                6
+            }
+    }
+    fn loses_to(&self) -> Self {
+        match self {
+            Rock => Paper,
+            Paper => Scissors,
+            Scissors => Rock,
+        }
+    }
+    fn wins_to(&self) -> Self {
+        match self {
+            Paper => Rock,
+            Scissors => Paper,
+            Rock => Scissors,
+        }
+    }
+}
+
 advent_of_code_macro::solve_problem!(
     day 2,
-    Input i32,
-    parse |_input: &str| {
-        1 + 1
+    Input Vec<Vec<char>>,
+    parse |input: &str| {
+        input.lines().map(|line| line.split(' ').map(|s| s.chars().next().unwrap()).collect()).collect()
     },
     part one |data: Input| {
-        data + 5
+        use super::Shape;
+        data.iter().map(|round| Shape::from_char(round[1]).result(&Shape::from_char(round[0]))).sum()
     },
     part two |data: Input| {
-        data + 10
+        use super::Shape;
+        data.iter().map(|round| match round[1] {
+            'X' =>  Shape::from_char(round[0]).wins_to().as_int(),
+            'Y' =>  Shape::from_char(round[0]).as_int() + 3,
+            'Z' =>  Shape::from_char(round[0]).loses_to().as_int() + 6,
+            _ => panic!("expected X, Y, or Z"),
+        }).sum()
     },
-    sample tests [7, 12],
-    star tests [7, 12]
+    sample tests [15, 12],
+    star tests [11063, 10349]
 );

2022/src/lib.rs

@@ -1,3 +1,3 @@
-#[allow(dead_code)]
+#![allow(dead_code)]
 mod day_1;
 mod day_2;