day1 part1

src/day1.rs

@@ -0,0 +1,32 @@
+#[aoc(day1, part1)]
+pub fn part1(input: &str) -> i32 {
+    let mut dial_counter = DialCounter {
+        position: 50,
+        zero_count: 0,
+    };
+    for line in input.lines() {
+        dial_counter.rotate(line)
+    }
+    dial_counter.zero_count
+}
+
+struct DialCounter {
+    position: i32,
+    zero_count: i32,
+}
+
+impl DialCounter {
+    fn rotate(&mut self, operation: &str) {
+        self.position = match operation.chars().nth(0).unwrap() {
+            'L' => (self.position - operation[1..].parse::<i32>().unwrap()) % 100,
+            'R' => (self.position + operation[1..].parse::<i32>().unwrap()) % 100,
+            _ => panic!("Unexpected input!"),
+        };
+        if self.position == 0 {
+            self.zero_count = self.zero_count + 1;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {}