[rust] Day 1 simplification

rust/src/day_01.rs

@@ -4,17 +4,16 @@ use std::str::Chars;
 use day::Day;
 
 pub struct Day01 {
-    input: String,
+    elevator: Elevator,
 }
 
 impl Day for Day01 {
     fn new(input: String) -> Day01 {
-        Day01 { input: input }
+        Day01 { elevator: Elevator::new(input) }
     }
 
     fn solve(&self) -> io::Result<i32> {
-        let elevator = Elevator::new(&self.input);
-        Ok(1 + elevator.run().position(|f| f == -1).unwrap_or(0) as i32)
+        Ok(1 + self.elevator.run().position(|f| f == -1).unwrap_or(0) as i32)
     }
 }
 
@@ -23,8 +22,8 @@ struct Elevator {
 }
 
 impl<'a> Elevator {
-    fn new(input: &String) -> Self {
-        Elevator { instructions: input.clone() }
+    fn new(input: String) -> Self {
+        Elevator { instructions: input }
     }
 
     fn run(self: &'a Self) -> ElevatorIterator<'a> {