From 67599b1cbc5f50ddeb5553c0f8c5ab60ae5698bf Mon Sep 17 00:00:00 2001
From: Donato Rimenti <donatohan.rimenti@gmail.com>
Date: Sat, 24 Feb 2018 14:05:44 +0100
Subject: [PATCH] - Extracted fitness function to separate class instead of
 Lambda - Cleaned up javadoc - Refactored fitness function code to add more
 significative variables names

---
 .../baeldung/algorithms/multiswarm/Swarm.java |  1 -
 .../multiswarm/LolFitnessFunction.java        | 52 +++++++++++++++++++
 .../multiswarm/MultiswarmUnitTest.java        | 44 ++++------------
 3 files changed, 62 insertions(+), 35 deletions(-)
 create mode 100644 algorithms/src/test/java/com/baeldung/algorithms/multiswarm/LolFitnessFunction.java

diff --git a/algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Swarm.java b/algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Swarm.java
index 56ab712a1d..e6d37bb7e6 100644
--- a/algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Swarm.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Swarm.java
@@ -3,7 +3,6 @@ package com.baeldung.algorithms.multiswarm;
 import java.util.Arrays;
 import java.util.Random;
 
-// TODO: Auto-generated Javadoc
 /**
  * Represents a collection of {@link Particle}.
  * 
diff --git a/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/LolFitnessFunction.java b/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/LolFitnessFunction.java
new file mode 100644
index 0000000000..726d4c135d
--- /dev/null
+++ b/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/LolFitnessFunction.java
@@ -0,0 +1,52 @@
+package com.baeldung.algorithms.multiswarm;
+
+/**
+ * Specific fitness function implementation to solve the League of Legends
+ * problem. This is the problem statement: <br>
+ * <br>
+ * In League of Legends, a player's Effective Health when defending against
+ * physical damage is given by E=H(100+A)/100, where H is health and A is armor.
+ * Health costs 2.5 gold per unit, and Armor costs 18 gold per unit. You have
+ * 3600 gold, and you need to optimize the effectiveness E of your health and
+ * armor to survive as long as possible against the enemy team's attacks. How
+ * much of each should you buy? <br>
+ * <br>
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class LolFitnessFunction implements FitnessFunction {
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see
+	 * com.baeldung.algorithms.multiswarm.FitnessFunction#getFitness(long[])
+	 */
+	@Override
+	public double getFitness(long[] particlePosition) {
+
+		long health = particlePosition[0];
+		long armor = particlePosition[1];
+
+		// No negatives values accepted.
+		if (health < 0 && armor < 0) {
+			return -(health * armor);
+		} else if (health < 0) {
+			return health;
+		} else if (armor < 0) {
+			return armor;
+		}
+
+		// Checks if the solution is actually feasible provided our gold.
+		double cost = (health * 2.5) + (armor * 18);
+		if (cost > 3600) {
+			return 3600 - cost;
+		} else {
+			// Check how good is the solution.
+			long fitness = (health * (100 + armor)) / 100;
+			return fitness;
+		}
+	}
+
+}
diff --git a/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/MultiswarmUnitTest.java b/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/MultiswarmUnitTest.java
index f1c1609a9e..3455cd3932 100644
--- a/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/MultiswarmUnitTest.java
+++ b/algorithms/src/test/java/com/baeldung/algorithms/multiswarm/MultiswarmUnitTest.java
@@ -22,46 +22,22 @@ public class MultiswarmUnitTest {
 	public MayFailRule mayFailRule = new MayFailRule();
 
 	/**
-	 * Tests the multiswarm algorithm with a generic problem.
-	 * 
-	 * The problem is the following:
-	 * 
+	 * Tests the multiswarm algorithm with a generic problem. The problem is the
+	 * following: <br>
+	 * <br>
 	 * In League of Legends, a player's Effective Health when defending against
 	 * physical damage is given by E=H(100+A)/100, where H is health and A is
-	 * armor.
-	 * 
-	 * Health costs 2.5 gold per unit, and Armor costs 18 gold per unit. You
-	 * have 3600 gold, and you need to optimize the effectiveness E of your
+	 * armor. Health costs 2.5 gold per unit, and Armor costs 18 gold per unit.
+	 * You have 3600 gold, and you need to optimize the effectiveness E of your
 	 * health and armor to survive as long as possible against the enemy team's
-	 * attacks. How much of each should you buy?
-	 * 
-	 * The solution is H = 1080, A = 50 for a total fitness of 1620.
-	 * 
-	 * Tested with 50 swarms each with 1000 particles.
+	 * attacks. How much of each should you buy? <br>
+	 * <br>
+	 * The solution is H = 1080, A = 50 for a total fitness of 1620. Tested with
+	 * 50 swarms each with 1000 particles.
 	 */
 	@Test
 	public void givenMultiswarm_whenThousandIteration_thenSolutionFound() {
-		Multiswarm multiswarm = new Multiswarm(50, 1000, values -> {
-
-			// No negatives values accepted.
-			if (values[0] < 0 && values[1] < 0) {
-				return -(values[0] * values[1]);
-			} else if (values[0] < 0) {
-				return values[0];
-			} else if (values[1] < 0) {
-				return values[1];
-			}
-
-			// Checks if the solution is actually feasible provided our gold.
-			double cost = (values[0] * 2.5) + (values[1] * 18);
-			if (cost > 3600) {
-				return 3600 - cost;
-			} else {
-				// Check how good is the solution.
-				long fitness = (values[0] * (100 + values[1])) / 100;
-				return fitness;
-			}
-		});
+		Multiswarm multiswarm = new Multiswarm(50, 1000, new LolFitnessFunction());
 
 		// Iterates 1000 times through the main loop and prints the result.
 		for (int i = 0; i < 1000; i++) {