DPSTree.java 2 KB
/**
 *
 */
package is2.data;

/**
 * @author Dr. Bernd Bohnet, 17.01.2011
 *
 *         Dynamic phrase structure tree.
 */
public class DPSTree {

	private int size = 0;

	public int[] heads;
	public int[] labels;

	public DPSTree() {
		this(30);
	}

	public DPSTree(int initialCapacity) {
		heads = new int[initialCapacity];
		labels = new int[initialCapacity];
	}

	/**
	 * Increases the capacity of this <tt>Graph</tt> instance, if necessary, to
	 * ensure that it can hold at least the number of nodes specified by the
	 * minimum capacity argument.
	 *
	 * @param minCapacity
	 *            the desired minimum capacity.
	 */
	private void ensureCapacity(int minCapacity) {

		if (minCapacity > heads.length) {

			int newCapacity = minCapacity + 1;

			if (newCapacity < minCapacity)
				newCapacity = minCapacity;
			int oldIndex[] = heads;
			heads = new int[newCapacity];
			System.arraycopy(oldIndex, 0, heads, 0, oldIndex.length);

			oldIndex = labels;
			labels = new int[newCapacity];
			System.arraycopy(oldIndex, 0, labels, 0, oldIndex.length);

		}
	}

	final public int size() {
		return size;
	}

	final public boolean isEmpty() {
		return size == 0;
	}

	final public void clear() {
		size = 0;
	}

	final public void createTerminals(int terminals) {
		ensureCapacity(terminals + 1);
		size = terminals + 1;
	}

	final public int create(int phrase) {

		ensureCapacity(size + 1);
		labels[size] = phrase;
		size++;
		return size - 1;
	}

	public int create(int phrase, int nodeId) {

		if (nodeId < 0)
			return this.create(phrase);
		// DB.println("create phrase "+nodeId+" label "+phrase);
		ensureCapacity(nodeId + 1);
		labels[nodeId] = phrase;
		if (size < nodeId)
			size = nodeId + 1;
		return nodeId;
	}

	public void createEdge(int i, int j) {
		heads[i] = j;
		// DB.println("create edge "+i+"\t "+j);
	}

	@Override
	public DPSTree clone() {
		DPSTree ps = new DPSTree(this.size + 1);

		for (int k = 0; k < size; k++) {
			ps.heads[k] = heads[k];
			ps.labels[k] = labels[k];
		}
		ps.size = size;
		return ps;

	}

}