update

java/src/DelaunayVoronoi.java

@@ -1,6 +1,6 @@
 import javax.swing.*;
 import java.awt.*;
-import java.awt.geom.Point2D;
+import java.awt.geom.*;
 import java.util.*;
 import java.util.List;
 import java.util.Queue;
@@ -201,7 +201,7 @@ void visitTriangles(TriangleVisitor triVisitor, boolean includeFrame) {
 		 * vertices are a unique set which includes
 		 * all vertices in the subdivision.
 		 * The frame vertices can be included if required.
-		 * <p/>
+		 * <p>
 		 * This is useful for algorithms which require traversing the
 		 * subdivision starting at all vertices.
 		 * Returning a quadedge for each vertex
@@ -268,7 +268,7 @@ List<Point.Double[]> getTriangles() {
 		/**
 		 * Gets a List of {@link Polygon}s for the Voronoi cells
 		 * of this triangulation.
-		 * <p/>
+		 * <p>
 		 * The userData of each polygon is set to be the {@link Point.Double)
 		 * of the cell site.  This allows easily associating external
 		 * data associated with the sites to the cells.
@@ -277,8 +277,8 @@ List<Point.Double[]> getTriangles() {
 		 * @return a List of Polygons
 		 */
 		List<Point.Double[]> getVoronoiCellPolygons() {
-      /*
-               * Compute circumcentres of triangles as vertices for dual edges.
+	  /*
+			   * Compute circumcentres of triangles as vertices for dual edges.
                * Precomputing the circumcentres is more efficient,
                * and more importantly ensures that the computed centres
                * are consistent across the Voronoi cells.
@@ -295,7 +295,7 @@ List<Point.Double[]> getVoronoiCellPolygons() {
 		/**
 		 * Gets the Voronoi cell around a site specified
 		 * by the origin of a QuadEdge.
-		 * <p/>
+		 * <p>
 		 * The userData of the polygon is set to be the {@link Point.Double)
 		 * of the site.  This allows attaching external
 		 * data associated with the site to this cell polygon.
@@ -562,21 +562,19 @@ Point.Double dest() {
 
 	// visualization
 	Random rnd = new Random(1);
-	JPanel panel;
 	List<Point.Double> points = new ArrayList<>();
 	List<Point2D.Double[]> tr = Collections.emptyList();
 	List<Point2D.Double[]> voronoiCellPolygons = Collections.emptyList();
 
-	public DelaunayVoronoi() throws HeadlessException {
+	public DelaunayVoronoi() {
 		int n = 100;
 		for (int i = 0; i < n; i++) {
 			int x = rnd.nextInt(950) + 1;
 			int y = rnd.nextInt(700) + 1;
 			Point.Double c = new Point.Double(x, y);
 			points.add(c);
 		}
-
-		panel = new JPanel() {
+		setContentPane(new JPanel() {
 			protected void paintComponent(Graphics g) {
 				super.paintComponent(g);
 				Graphics2D g2 = ((Graphics2D) g);
@@ -602,31 +600,26 @@ protected void paintComponent(Graphics g) {
 					g.drawOval((int) point.x - 2, (int) point.y - 2, 5, 5);
 				}
 			}
-		};
-		setContentPane(panel);
-	}
-
-	public static void main(String[] args) {
-		final DelaunayVoronoi dv = new DelaunayVoronoi();
-		dv.setSize(new Dimension(1024, 768));
-		dv.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
-		dv.setVisible(true);
+		});
+		setSize(new Dimension(1024, 768));
+		setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
+		setVisible(true);
 		new Thread() {
 			public void run() {
 				while (true) {
-					final Point2D.Double pivot = dv.points.get(0);
-					pivot.x += dv.rnd.nextInt(4);
-					pivot.y += dv.rnd.nextInt(2);
+					final Point2D.Double pivot = points.get(0);
+					pivot.x += rnd.nextInt(4);
+					pivot.y += rnd.nextInt(2);
 					pivot.x %= 950;
 					pivot.y %= 700;
 
-					Set<Point.Double> uniquePoints = new HashSet<>(dv.points);
+					Set<Point.Double> uniquePoints = new HashSet<>(points);
 					SubDivision subdivision = new SubDivision(uniquePoints);
 					for (Point.Double p : uniquePoints) subdivision.insertSite(p);
-					dv.tr = subdivision.getTriangleCoordinates();
-					dv.voronoiCellPolygons = subdivision.getVoronoiCellPolygons();
+					tr = subdivision.getTriangleCoordinates();
+					voronoiCellPolygons = subdivision.getVoronoiCellPolygons();
 
-					dv.panel.repaint();
+					repaint();
 					try {
 						Thread.sleep(15);
 					} catch (InterruptedException e) {
@@ -636,4 +629,8 @@ public void run() {
 			}
 		}.start();
 	}
-}
+
+	public static void main(String[] args) {
+		new DelaunayVoronoi();
+	}
+}

java/src/Inversions.java

@@ -21,7 +21,7 @@ public static int inversions(int[] a, int low, int high) {
 
 	// random test
 	public static void main(String[] args) {
-		Random rnd = new Random();
+		Random rnd = new Random(1);
 		for (int step = 0; step < 1000; step++) {
 			int n = rnd.nextInt(100);
 			int[] p = new int[n];

java/src/KdTreePointQuery.java

@@ -47,7 +47,7 @@ else if (n > k)
 		}
 	}
 
-	static final Random rnd = new Random();
+	static final Random rnd = new Random(1);
 
 	static int randomizedPartition(Point[] a, int low, int high, boolean divX) {
 		swap(a, low + rnd.nextInt(high - low), high - 1);

java/src/KdTreeRectQuery.java

@@ -66,7 +66,7 @@ else if (n > k)
 		}
 	}
 
-	static final Random rnd = new Random();
+	static final Random rnd = new Random(1);
 
 	static int randomizedPartition(Point[] a, int low, int high, boolean divX) {
 		swap(a, low + rnd.nextInt(high - low), high - 1);

java/src/Lca.java

@@ -73,7 +73,7 @@ int minPos(int a, int b, int node, int left, int right) {
 
 	// Random test
 	public static void main(String[] args) {
-		Random rnd = new Random();
+		Random rnd = new Random(1);
 		for (int step = 0; step < 1000; step++) {
 			int n = rnd.nextInt(50) + 1;
 			List<Integer>[] tree = getRandomTree(n, rnd);

java/src/MaxMatchingRandomized.java

@@ -43,7 +43,7 @@ static int rank(int[][] a) {
 	public static int maxMatching(boolean[][] d) {
 		int n = d.length;
 		int[][] a = new int[n][n];
-		Random rnd = new Random();
+		Random rnd = new Random(1);
 		for (int i = 0; i < n; i++) {
 			for (int j = 0; j < i; j++) {
 				if (d[i][j]) {

java/src/NthElement.java

@@ -15,7 +15,7 @@ else if (n > k)
 		}
 	}
 
-	static Random rnd = new Random();
+	static Random rnd = new Random(1);
 
 	static int randomizedPartition(int[] a, int low, int high) {
 		swap(a, low + rnd.nextInt(high - low), high - 1);

java/src/Partition.java

@@ -2,7 +2,7 @@
 
 public class Partition {
 
-	static Random rnd = new Random();
+	static Random rnd = new Random(1);
 
 	public static int randomizedPartition(int[] a, int low, int high) {
 		swap(a, low + rnd.nextInt(high - low), high - 1);

java/src/PointLocation.java

@@ -3,6 +3,7 @@
 public class PointLocation {
 
 	public static int[] locatePoints(int[][] polygonX, int[][] polygonY, int[] qx, int[] qy) {
+		// preprocessing
 		Map<Long, Integer> endPoints = new HashMap<>();
 		Map<Integer, NavigableSet<Segment>> verticalSegments = new HashMap<>();
 		List<Event> events = new ArrayList<>();
@@ -23,8 +24,8 @@ public static int[] locatePoints(int[][] polygonX, int[][] polygonY, int[] qx, i
 			}
 		}
 		Collections.sort(events, eventComparator);
-		Treap[] treaps = new Treap[events.size()];
 		int[] eventsX = new int[events.size()];
+		Treap[] treaps = new Treap[events.size()];
 		int cnt = 0;
 		Treap treap = null;
 		for (Event event : events) {
@@ -38,6 +39,7 @@ public static int[] locatePoints(int[][] polygonX, int[][] polygonY, int[] qx, i
 			eventsX[cnt - 1] = event.x;
 			treaps[cnt - 1] = treap;
 		}
+		// answering queries
 		int[] res = new int[qx.length];
 		for (int i = 0; i < qx.length; i++) {
 			Integer polygonId = endPoints.get(((long) qx[i] << 32) + qy[i]);
@@ -146,7 +148,7 @@ static long cross(long ax, long ay, long bx, long by, long cx, long cy) {
 		return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax);
 	}
 
-	static Random random = new Random();
+	static Random random = new Random(1);
 
 	// persistent treap
 	static class Treap {

java/src/PointLocationOffline.java

@@ -135,7 +135,7 @@ static long cross(long ax, long ay, long bx, long by, long cx, long cy) {
 		return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax);
 	}
 
-	static Random random = new Random();
+	static Random random = new Random(1);
 
 	static class Treap {
 		Segment key;