Graphs and paths - Data Structures and Problem Solving Using Java - page 538

1 /**
2 * Initializes the vertex output info prior to running
3 * any shortest path algorithm.
4 */
5 private void clearAll( )
6 {
7 for( Vertex v : vertexMap.values( ) )
8 v.reset( );
9 }

figure 14.11
Private routine for
initializing the output
members for use by
the shortest-path
algorithms

1 /**
2 * Recursive routine to print shortest path to dest
3 * after running shortest path algorithm. The path
4 * is known to exist.
5 */
6 private void printPath( Vertex dest )
7 {
8 if( dest.prev != null )
9 {
10 printPath( dest.prev );
11 System.out.print( " to " );
12 }
13 System.out.print( dest.name );
14 }

figure 14.12
A recursive routine for
printing the shortest
path

1 /**
2 * Driver routine to handle unreachables and print total cost.
3 * It calls recursive routine to print shortest path to
4 * destNode after a shortest path algorithm has run.
5 */
6 public void printPath( String destName )
7 {
8 Vertex w = vertexMap.get( destName );
9 if( w == null )
10 throw new NoSuchElementException( );
11 else if( w.dist == INFINITY )
12 System.out.println( destName + " is unreachable" );
13 else
14 {
15 System.out.print( "(Cost is: " + w.dist + ") " );
16 printPath( w );
17 System.out.println( );
18 }
19 }

figure 14.13
A routine for printing
the shortest path by
consulting the graph
table (see Figure
14.5)