Lengua: Java
Puntuación: 555 533
Solo intenté forzar una solución por fuerza bruta iterando sobre las formas en orden de área decreciente (perímetro en caso de empate) y probando todas las posibilidades de empaque hasta que se encuentre un empaque válido para esa forma, en cuyo punto se fija la posición de la forma. y el algoritmo pasa a la siguiente forma. Con el fin de mejorar la calidad del resultado cuando se busca un embalaje válido, primero se intentan todas las posiciones posibles con la forma girada de manera que sea más alta que ancha.
Nota: esto supone que las imágenes de entrada tienen todas las formas separadas por espacios en blanco. Toma el ancho máximo de la salida como primer argumento y una lista de imágenes de forma como los otros argumentos (cada imagen de forma puede tener una o más formas separadas por al menos una línea de píxeles blancos)
import java.awt.Color;
import java.awt.Graphics;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Set;
import javax.imageio.ImageIO;
public class Packer {
public static void main(String[] args) throws Exception {
long t1 = System.currentTimeMillis();
int width = Integer.valueOf(args[0]);
List<Item> itemList = new ArrayList<Item>();
for (int i = 1; i < args.length; i++) {
itemList.addAll(getItems(ImageIO.read(new File(args[i]))));
}
File outputFile = new File("output.png");
if (outputFile.exists()) {
outputFile.delete();
}
outputFile.createNewFile();
ImageIO.write(pack(itemList, width), "PNG", outputFile);
long t2 = System.currentTimeMillis();
System.out.println("Finished in " + (t2 - t1) + "ms");
}
private static BufferedImage pack(List<Item> itemList, int width) {
System.out.println("Packing " + itemList.size() + " items");
Collections.sort(itemList, new Comparator<Item>() {
@Override
public int compare(Item o1, Item o2) {
return o1.area < o2.area ? 1 : (o1.area > o2.area ? -1
: (o1.perimiter < o2.perimiter ? 1
: (o1.perimiter > o2.perimiter ? -1 : 0)));
}
});
Packing packing = new Packing(width);
PackedItem.Rotation[] widthRots = { PackedItem.Rotation.ZERO,
PackedItem.Rotation.ONE_EIGHTY };
PackedItem.Rotation[] heightRots = { PackedItem.Rotation.NINETY,
PackedItem.Rotation.TWO_SEVENTY };
int count = 0;
for (Item item : itemList) {
count++;
int minSize = Math.min(item.width, item.height);
int maxSize = Math.max(item.width, item.height);
int x = 0;
int y = 0;
int rot = 0;
PackedItem.Rotation[] rots = widthRots;
if (item.width > item.height) {
rots = heightRots;
}
boolean rotsSwitched = false;
PackedItem packedItem = new PackedItem(item, rots[rot], x, y);
System.out.format("Packing item %d which is %d by %d\n", count,
item.width, item.height);
while (!packing.isValidWith(packedItem)) {
if (rot == 0) {
rot = 1;
} else {
rot = 0;
if (x + minSize >= width) {
x = 0;
y++;
if (!rotsSwitched
&& y + maxSize > packing.height) {
rotsSwitched = true;
if (item.width > item.height) {
rots = widthRots;
} else {
rots = heightRots;
}
y = 0;
}
} else {
x++;
}
}
packedItem.set(x, y, rots[rot]);
}
packing.addItem(packedItem);
System.out.format("Packed item %d\n", count);
}
return packing.getDrawing();
}
private static List<Item> getItems(BufferedImage image) {
List<Item> itemList = new ArrayList<Item>();
boolean[][] pointsProcessed = new boolean[image.getWidth()][image
.getHeight()];
for (int i = 0; i < image.getWidth(); i++) {
for (int j = 0; j < image.getHeight(); j++) {
if (pointsProcessed[i][j]) {
continue;
}
ImagePoint point = ImagePoint.getPoint(i, j, image);
if (point.getColor().equals(Color.WHITE)) {
pointsProcessed[point.x][point.y] = true;
continue;
}
Collection<ImagePoint> itemPoints = new ArrayList<ImagePoint>();
Queue<ImagePoint> pointsToProcess = new LinkedList<ImagePoint>();
pointsToProcess.add(point);
while (!pointsToProcess.isEmpty()) {
point = pointsToProcess.poll();
if (pointsProcessed[point.x][point.y]) {
continue;
}
pointsProcessed[point.x][point.y] = true;
if (point.getColor().equals(Color.WHITE)) {
continue;
}
itemPoints.add(point);
pointsToProcess.addAll(point.getNeighbors());
}
itemList.add(new Item(itemPoints));
}
}
return itemList;
}
private interface Point {
int getX();
int getY();
Color getColor();
}
private static final class ImagePoint implements Point {
private static final Map<BufferedImage, Map<Integer, Map<Integer, ImagePoint>>> POINT_CACHE = new HashMap<BufferedImage, Map<Integer, Map<Integer, ImagePoint>>>();
private final int x;
private final int y;
private final Color color;
private final BufferedImage image;
private Collection<ImagePoint> neighbors;
private ImagePoint(int x, int y, BufferedImage image) {
this.x = x;
this.y = y;
this.image = image;
this.color = new Color(image.getRGB(x, y));
}
static ImagePoint getPoint(int x, int y, BufferedImage image) {
Map<Integer, Map<Integer, ImagePoint>> imageCache = POINT_CACHE
.get(image);
if (imageCache == null) {
imageCache = new HashMap<Integer, Map<Integer, ImagePoint>>();
POINT_CACHE.put(image, imageCache);
}
Map<Integer, ImagePoint> xCache = imageCache.get(x);
if (xCache == null) {
xCache = new HashMap<Integer, Packer.ImagePoint>();
imageCache.put(x, xCache);
}
ImagePoint point = xCache.get(y);
if (point == null) {
point = new ImagePoint(x, y, image);
xCache.put(y, point);
}
return point;
}
Collection<ImagePoint> getNeighbors() {
if (neighbors == null) {
neighbors = new ArrayList<ImagePoint>();
for (int i = -1; i <= 1; i++) {
if (x + i < 0 || x + i >= image.getWidth()) {
continue;
}
for (int j = -1; j <= 1; j++) {
if ((i == j && i == 0) || y + j < 0
|| y + j >= image.getHeight()) {
continue;
}
neighbors.add(getPoint(x + i, y + j, image));
}
}
}
return neighbors;
}
@Override
public int getX() {
return y;
}
@Override
public int getY() {
return x;
}
@Override
public Color getColor() {
return color;
}
}
private static final class Item {
private final Collection<ItemPoint> points;
private final int width;
private final int height;
private final int perimiter;
private final int area;
Item(Collection<ImagePoint> points) {
int maxX = Integer.MIN_VALUE;
int minX = Integer.MAX_VALUE;
int maxY = Integer.MIN_VALUE;
int minY = Integer.MAX_VALUE;
for (ImagePoint point : points) {
maxX = Math.max(maxX, point.x);
minX = Math.min(minX, point.x);
maxY = Math.max(maxY, point.y);
minY = Math.min(minY, point.y);
}
this.width = maxX - minX;
this.height = maxY - minY;
this.perimiter = this.width * 2 + this.height * 2;
this.area = this.width * this.height;
this.points = new ArrayList<ItemPoint>(points.size());
for (ImagePoint point : points) {
this.points.add(new ItemPoint(point.x - minX, point.y - minY,
point.getColor()));
}
}
private static final class ItemPoint implements Point {
private final int x;
private final int y;
private final Color color;
public ItemPoint(int x, int y, Color color) {
this.x = x;
this.y = y;
this.color = color;
}
@Override
public int getX() {
return x;
}
@Override
public int getY() {
return y;
}
@Override
public Color getColor() {
return color;
}
}
}
private static final class PackedItem {
private final Collection<PackedPoint> points;
private Rotation rotation;
private int x;
private int y;
private AffineTransform transform;
private int modCount;
PackedItem(Item item, Rotation rotation, int x, int y) {
this.set(x, y, rotation);
this.points = new ArrayList<PackedPoint>();
for (Point point : item.points) {
this.points.add(new PackedPoint(point));
}
}
void set(int newX, int newY, Rotation newRotation) {
modCount++;
x = newX;
y = newY;
rotation = newRotation;
transform = new AffineTransform();
transform.translate(x, y);
transform.rotate(this.rotation.getDegrees());
}
void draw(Graphics g) {
Color oldColor = g.getColor();
for (Point point : points) {
g.setColor(point.getColor());
g.drawLine(point.getX(), point.getY(), point.getX(),
point.getY());
}
g.setColor(oldColor);
}
private enum Rotation {
ZERO(0), NINETY(Math.PI / 2), ONE_EIGHTY(Math.PI), TWO_SEVENTY(
3 * Math.PI / 2);
private final double degrees;
Rotation(double degrees) {
this.degrees = degrees;
}
double getDegrees() {
return degrees;
}
}
private final class PackedPoint implements Point {
private final Point point;
private final Point2D point2D;
private int x;
private int y;
private int modCount;
public PackedPoint(Point point) {
this.point = point;
this.point2D = new Point2D.Float(point.getX(), point.getY());
}
@Override
public int getX() {
update();
return x;
}
@Override
public int getY() {
update();
return y;
}
private void update() {
if (this.modCount != PackedItem.this.modCount) {
this.modCount = PackedItem.this.modCount;
Point2D destPoint = new Point2D.Float();
transform.transform(point2D, destPoint);
x = (int) destPoint.getX();
y = (int) destPoint.getY();
}
}
@Override
public Color getColor() {
return point.getColor();
}
}
}
private static final class Packing {
private final Set<PackedItem> packedItems = new HashSet<PackedItem>();
private final int maxWidth;
private boolean[][] pointsFilled;
private int height;
Packing(int maxWidth) {
this.maxWidth = maxWidth;
this.pointsFilled = new boolean[maxWidth][0];
}
void addItem(PackedItem item) {
packedItems.add(item);
for (Point point : item.points) {
height = Math.max(height, point.getY() + 1);
if (pointsFilled[point.getX()].length < point.getY() + 1) {
pointsFilled[point.getX()] = Arrays.copyOf(
pointsFilled[point.getX()], point.getY() + 1);
}
pointsFilled[point.getX()][point.getY()] = true;
}
}
BufferedImage getDrawing() {
BufferedImage image = new BufferedImage(maxWidth, height,
BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
g.setColor(Color.WHITE);
g.drawRect(0, 0, maxWidth, height);
for (PackedItem item : packedItems) {
item.draw(g);
}
return image;
}
boolean isValidWith(PackedItem item) {
for (Point point : item.points) {
int x = point.getX();
int y = point.getY();
if (y < 0 || x < 0 || x >= maxWidth) {
return false;
}
boolean[] column = pointsFilled[x];
if (y < column.length && column[y]) {
return false;
}
}
return true;
}
}
}
La solución que esto produce (toma aproximadamente 4 minutos y 30 segundos en mi máquina) es:
Al ver esta imagen, parece que el resultado puede mejorarse iterando sobre todas las formas después del empaquetado e intentando moverlas un poco hacia arriba. Podría intentar hacer eso más tarde.
