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diff --git a/watchmaker/examples/src/java/main/org/uncommons/watchmaker/examples/travellingsalesman/RouteEvaluator.java b/watchmaker/examples/src/java/main/org/uncommons/watchmaker/examples/travellingsalesman/RouteEvaluator.java
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+//=============================================================================
+// Copyright 2006-2010 Daniel W. Dyer
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//=============================================================================
+package org.uncommons.watchmaker.examples.travellingsalesman;
+
+import java.util.List;
+import org.uncommons.watchmaker.framework.FitnessEvaluator;
+
+/**
+ * Fitness evalator that measures the total distance of a route in the travelling salesman
+ * problem.  The fitness score of a route is the total distance (in km).  A route
+ * is represented as a list of cities in the order that they will be visited.
+ * The last leg of the journey is from the last city in the list back to the
+ * first.
+ * @author Daniel Dyer
+ */
+public class RouteEvaluator implements FitnessEvaluator<List<String>>
+{
+    private final DistanceLookup distances;
+
+
+    /**
+     * @param distances Provides distances between a set of cities.
+     */
+    public RouteEvaluator(DistanceLookup distances)
+    {
+        this.distances = distances;
+    }
+
+
+    /**
+     * Calculates the length of an evolved route. 
+     * @param candidate The route to evaluate.
+     * @param population {@inheritDoc}
+     * @return The total distance (in kilometres) of a journey that visits
+     * each city in order and returns to the starting point.
+     */
+    public double getFitness(List<String> candidate,
+                             List<? extends List<String>> population)
+    {
+        int totalDistance = 0;
+        int cityCount = candidate.size();
+        for (int i = 0; i < cityCount; i++)
+        {
+            int nextIndex = i < cityCount - 1 ? i + 1 : 0;
+            totalDistance += distances.getDistance(candidate.get(i),
+                                                   candidate.get(nextIndex));
+        }
+        return totalDistance;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     * Returns false since shorter distances represent fitter candidates.
+     * @return false
+     */
+    public boolean isNatural()
+    {
+        return false;
+    }
+}