Aggiunto graph

graph/Graph.java

@@ -0,0 +1,55 @@
+package graph;
+
+import exceptions.InvalidPositionException;
+
+/**
+ * An interface for a graph.
+ * @author Roberto Tamassia
+ */
+
+public interface Graph<V, E> {
+
+  /** Returns the number of vertices of the graph */
+  public int numVertices();
+
+  /** Returns the number of edges of the graph */
+  public int numEdges();
+
+  /** Returns the vertices of the graph as an iterable collection */
+  public Iterable<Vertex<V>> vertices();
+
+  /** Returns the edges of the graph as an iterable collection */
+  public Iterable<Edge<E>> edges();
+
+  /** Replaces the element of a given vertex with a new element and returns the old element */
+  public V replace(Vertex<V> p, V o) throws InvalidPositionException;
+
+  /** Replaces the element of a given edge with a new element and  returns the old element */
+  public E replace(Edge<E> p, E o) throws InvalidPositionException;
+
+  /** Returns the edges incident on a vertex as an iterable collection */
+  public Iterable<Edge<E>> incidentEdges(Vertex<V> v)   throws InvalidPositionException;
+
+  /** Returns the endvertices of a vertex as an array of length 2 */
+  public Vertex[] endVertices(Edge<E> e) throws InvalidPositionException;
+
+  /** Returns the other endvertex of an incident edge */
+  public Vertex<V> opposite(Vertex<V> v, Edge<E> e)  throws InvalidPositionException;
+
+  /** Tests whether two vertices are adjacent */
+  public boolean areAdjacent(Vertex<V> u, Vertex<V> v)  throws InvalidPositionException;
+
+  /** Inserts and return a new vertex with a given element */
+  public Vertex<V> insertVertex(V o);
+
+  /** Inserts and return a new edge with a given element between two  vertices */
+  public Edge<E> insertEdge(Vertex<V> u, Vertex<V> v, E o)  throws InvalidPositionException;
+
+  /** Removes a vertex and all its incident edges and returns the  element stored at the removed vertex */
+  public V removeVertex(Vertex<V> v) throws InvalidPositionException;
+
+  /** Removes an edge and return its element */
+  public E removeEdge(Edge<E> e) throws InvalidPositionException;
+}
+
+