Adding analyzer feedback for need for speed concept exercise

exercises/concept/need-for-speed/.meta/design.md

@@ -2,29 +2,33 @@
 
 ## Learning objectives
 
-- Know what classes are.
-- Know what encapsulation is.
-- Know what fields are.
-- Know how to create an object.
-- Know how to update state through methods.
-- Know about the `void` type.
+- Know what constructors are.
+- Know how to create a constructor.
+- Know how to initialize a new instance of a class.
+- Know how to differentiate them with normal methods.
 
 ## Out of scope
 
-- Reference equality.
-- Constructors.
-- Interfaces.
-- Inheritance.
-- Finalizers.
 - Method overloading.
+- No arguments constructor.
 
 ## Concepts
 
-- `classes`: know what classes are; know what encapsulation is; know what fields are; know how to create an object; know how to update state through methods; know about the `void` type.
+- `constructors`: Know how to create `constructors` and what they are.
 
 ## Prerequisites
 
 - `basics`: know how to define a basic class with basic methods.
-- `strings`: know how to do basic string interpolation.
-- `numbers`: know how to compare numbers.
 - `conditionals`: know how to do conditional logic.
+- `classes`: know how classes work.
+
+## Analyzer
+
+This exercise could benefit from the following rules in the [analyzer]:
+
+- `actionable`: If the student used a loop in the `tryFinishTrack()` method, encourage it to explore a different approach.
+
+If the solution does not receive any of the above feedback, it must be exemplar.
+Leave a `celebratory` comment to celebrate the success!
+
+[analyzer]: https://github.com/exercism/java-analyzer

exercises/concept/need-for-speed/.meta/src/reference/java/NeedForSpeed.java

@@ -21,6 +21,18 @@ public int distanceDriven() {
         return distance;
     }
 
+    public int getSpeed() {
+        return speed;
+    }
+
+    public int getBatteryDrain() {
+        return batteryDrain;
+    }
+
+    public int getCurrentBattery() {
+        return battery;
+    }
+
     public void drive() {
         if (!batteryDrained()) {
             battery -= batteryDrain;
@@ -37,14 +49,6 @@ class RaceTrack {
     }
 
     public boolean tryFinishTrack(NeedForSpeed car) {
-        while (car.distanceDriven() < distance) {
-            if (car.batteryDrained()) {
-                return false;
-            }
-
-            car.drive();
-        }
-
-        return true;
+        return ((double) distance / car.getSpeed()) <= (car.getCurrentBattery() / car.getBatteryDrain());
     }
 }