/*
* Created on Feb 3, 2007
*
* Copyright (c) 2007, the JUNG Project and the Regents of the University
* of California
* All rights reserved.
*
* This software is open-source under the BSD license; see either
* "license.txt" or
* http://jung.sourceforge.net/license.txt for a description.
*/
package edu.uci.ics.jung.graph;
/**
* A subtype of <code>Graph</code> which is a (directed, rooted) tree. What we
* refer to as a "tree" here is actually (in the terminology of graph theory) a
* rooted tree. (That is, there is a designated single vertex--the <i>root</i>
* --from which we measure the shortest path to each vertex, which we call its
* <i>depth</i>; the maximum over all such depths is the tree's <i>height</i>.
* Note that for a tree, there is exactly one unique path from the root to any
* vertex.)
*
* @author Joshua O'Madadhain
*/
public interface Tree<V, E> extends Forest<V, E> {
/**
* Returns the (unweighted) distance of <code>vertex</code> from the root of
* this tree.
*
* @param vertex
* the vertex whose depth is to be returned.
* @return the length of the shortest unweighted path from
* <code>vertex</code> to the root of this tree
* @see #getHeight()
*/
public int getDepth(V vertex);
/**
* Returns the maximum depth in this tree.
*
* @return the maximum depth in this tree
* @see #getDepth(Object)
*/
public int getHeight();
/**
* Returns the root of this tree. The root is defined to be the vertex
* (designated either at the tree's creation time, or as the first vertex to
* be added) with respect to which vertex depth is measured.
*
* @return the root of this tree
*/
public V getRoot();
}