structure5 Class GraphListDirected<V,E>

```java.lang.Object
structure5.AbstractStructure<V>
structure5.GraphList<V,E>
structure5.GraphListDirected<V,E>
```
All Implemented Interfaces:
Iterable<V>, Graph<V,E>, Structure<V>

`public class GraphListDirected<V,E>extends GraphList<V,E>`

A GraphListDirected is a list-based graph representation that consists of a collection of vertices and directed edges. Portions of the graph may be marked visited to support iterative algorithms. Iteration is provided over vertices, edges, and vertices adjacent to a particular vertex.

Example Usage:

To create a graph representation of the movie theaters nearest the Williams College Department of Computer Science's unix laboratory, and to print these theaters out in order of increasing distance, we could use the following:

```  public static void main(String[] argv){
Graph theaters = new `GraphListDirected()`;
FibHeap heap = new FibHeap();

//instantiate array of locations
String[] locations = new String[]{"TCL 312", "Images Cinema",
"Movie Plex 3", "Cinema 1,2,&3",
"Cinema 7", "Berkshire Mall Cinemas"
,"Hathaway's Drive Inn Theatre",
"Hollywood Drive-In Theatre"};

//instantiate array of distances between `location[0]`
//and movie theaters
double[] distances =  new double[]{-1, 0.0, 12.6, 12.9, 12.9,
14.7, 16.5, 18.0};

//build graph
for(int i=0; i < locations.length; i++) theaters.add(locations[i]);
for(int i=1; i < distances.length; i++){
theaters.`addEdge(locations[0],locations[i],new Double(distances[i]))`;
}

//place neighbors of lab in into priority queue
for(Iterator i=theaters.`neighbors(locations[0])`; i.hasNext();){
Object theater = i.next();
Object distance = theaters.`getEdge(locations[0], theater).label()`;
}

//print out theaters in order of distance
while(!heap.isEmpty()){
ComparableAssociation show = (ComparableAssociation)heap.remove();
System.out.println(show.getValue()+" is "+show.getKey()+" miles away.");
}
}
```

`GraphList`, `GraphListUndirected`, `GraphMatrixDirected`

Constructor Summary
`GraphListDirected()`
Construct a directed, adjacency-list based graph.

Method Summary
` void` ```addEdge(V vLabel1, V vLabel2, E label)```
Add an edge between two vertices within the graph.
` int` `edgeCount()`
Determine the number of edges in graph.
` V` `remove(V label)`
Remove a vertex from the graph.
` E` ```removeEdge(V vLabel1, V vLabel2)```
Remove possible edge between vertices labeled vLabel1 and vLabel2.
` String` `toString()`
Construct a string representation of graph.

Methods inherited from class structure5.GraphList
`add, clear, contains, containsEdge, degree, edges, get, getEdge, isDirected, isEmpty, isVisited, isVisitedEdge, iterator, main, neighbors, reset, size, visit, visitEdge`

Methods inherited from class structure5.AbstractStructure
`elements, hashCode, values`

Methods inherited from class java.lang.Object
`equals, getClass, notify, notifyAll, wait, wait, wait`

Methods inherited from interface structure5.Structure
`elements, values`

Constructor Detail

GraphListDirected

`public GraphListDirected()`
Construct a directed, adjacency-list based graph.

Method Detail

```public void addEdge(V vLabel1,
V vLabel2,
E label)```
Add an edge between two vertices within the graph. Edge is directed. Duplicate edges are silently replaced. Labels on edges may be null.

Specified by:
`addEdge` in interface `Graph<V,E>`
Specified by:
`addEdge` in class `GraphList<V,E>`
Parameters:
`vLabel1` - Source vertex.
`vLabel2` - Destination vertex.
`label` - Label associated with the edge.

remove

`public V remove(V label)`
Remove a vertex from the graph. Associated edges are also removed. Non-vertices are silently ignored.

Specified by:
`remove` in interface `Graph<V,E>`
Specified by:
`remove` in interface `Structure<V>`
Specified by:
`remove` in class `GraphList<V,E>`
Parameters:
`label` - The label of the vertex within the graph.
Returns:
The label associated with the vertex.

removeEdge

```public E removeEdge(V vLabel1,
V vLabel2)```
Remove possible edge between vertices labeled vLabel1 and vLabel2. vLabel1 is the source.

Specified by:
`removeEdge` in interface `Graph<V,E>`
Specified by:
`removeEdge` in class `GraphList<V,E>`
Parameters:
`vLabel1` - Source vertex.
`vLabel2` - Destination vertex.
Returns:
The label associated with the edge removed.

edgeCount

`public int edgeCount()`
Determine the number of edges in graph.

Specified by:
`edgeCount` in interface `Graph<V,E>`
Specified by:
`edgeCount` in class `GraphList<V,E>`
Returns:
Number of edges in graph.

toString

`public String toString()`
Construct a string representation of graph.

Overrides:
`toString` in class `Object`
Returns:
String representing graph.