data_structures_free

net/datastructures/ConnectivityDFS.java

@@ -0,0 +1,24 @@
+package net.datastructures;
+import java.util.Iterator;
+import java.lang.Boolean;
+
+//begin#fragment ConnectivityTesterDFS
+/** This class specializes DFS to determine whether the graph is connected. */
+public class ConnectivityDFS<V, E> extends DFS <V, E, Object, Boolean> {
+  protected int reached;
+//end#fragment ConnectivityTesterDFS
+  /** Executes the DFS algorithm. 
+   * @param graph Input graph
+   * @param start Start vertex
+   * @param info unused
+   * @return {@link Boolean} with value <tt>true</tt> if the graph is
+   * connected, <tt>false</tt> otherwise
+   */
+//begin#fragment ConnectivityTesterDFS
+  protected void setup() { reached = 0; }
+  protected void startVisit(Vertex<V> v) { reached++; }
+  protected Boolean finalResult(Boolean dfsResult) { 
+    return new Boolean(reached == graph.numVertices());
+  }
+}
+//end#fragment ConnectivityTesterDFS