Initial data commit

Task/K-d-tree/Java/k-d-tree-3.java

@@ -0,0 +1,48 @@
+import java.util.*;
+
+public class KdTreeTest {
+    public static void main(String[] args) {
+        testWikipedia();
+        System.out.println();
+        testRandom(1000);
+        System.out.println();
+        testRandom(1000000);
+    }
+
+    private static void testWikipedia() {
+        double[][] coords = {
+            { 2, 3 }, { 5, 4 }, { 9, 6 }, { 4, 7 }, { 8, 1 }, { 7, 2 }
+        };
+        List<KdTree.Node> nodes = new ArrayList<>();
+        for (int i = 0; i < coords.length; ++i)
+            nodes.add(new KdTree.Node(coords[i]));
+        KdTree tree = new KdTree(2, nodes);
+        KdTree.Node nearest = tree.findNearest(new KdTree.Node(9, 2));
+        System.out.println("Wikipedia example data:");
+        System.out.println("nearest point: " + nearest);
+        System.out.println("distance: " + tree.distance());
+        System.out.println("nodes visited: " + tree.visited());
+    }
+
+    private static KdTree.Node randomPoint(Random random) {
+        double x = random.nextDouble();
+        double y = random.nextDouble();
+        double z = random.nextDouble();
+        return new KdTree.Node(x, y, z);
+    }
+
+    private static void testRandom(int points) {
+        Random random = new Random();
+        List<KdTree.Node> nodes = new ArrayList<>();
+        for (int i = 0; i < points; ++i)
+            nodes.add(randomPoint(random));
+        KdTree tree = new KdTree(3, nodes);
+        KdTree.Node target = randomPoint(random);
+        KdTree.Node nearest = tree.findNearest(target);
+        System.out.println("Random data (" + points + " points):");
+        System.out.println("target: " + target);
+        System.out.println("nearest point: " + nearest);
+        System.out.println("distance: " + tree.distance());
+        System.out.println("nodes visited: " + tree.visited());
+    }
+}