1+ // USE GRAPH FILE FROM GRAPH FOLDER
2+ 3+ import java .util .ArrayList ;
4+ 5+ class GraphTraverser {
6+ // QUEUE
7+ public class Queue {
8+ 9+ public LinkedList queue ;
10+ public int size ;
11+ 12+ public Queue () {
13+ this .queue = new LinkedList ();
14+ this .size = 0 ;
15+ }
16+ 17+ public boolean isEmpty () {
18+ return this .size == 0 ;
19+ }
20+ 21+ public void enqueue (Vertex data ) {
22+ this .queue .addToTail (data );
23+ this .size ++;
24+ }
25+ 26+ public Vertex peek () {
27+ if (this .isEmpty ()) {
28+ return null ;
29+ } else {
30+ return this .queue .head .data ;
31+ }
32+ }
33+ 34+ public Vertex dequeue () {
35+ if (!this .isEmpty ()) {
36+ Vertex data = this .queue .removeHead ();
37+ this .size --;
38+ return data ;
39+ } else {
40+ throw new Error ("LinearDataStructures.Queues.Queue is empty!" );
41+ }
42+ }
43+ 44+ }
45+ 46+ // GRAPH TRAVERSER
47+ public static void depthFirstTraversal (Vertex start , ArrayList <Vertex > visitedVertices ) {
48+ System .out .println (start .getData ());
49+ 50+ for (Edge e : start .getEdges ()) {
51+ Vertex neighbor = e .getEnd ();
52+ 53+ if (!visitedVertices .contains (neighbor )) {
54+ visitedVertices .add (neighbor );
55+ GraphTraverser .depthFirstTraversal (neighbor , visitedVertices );
56+ }
57+ }
58+ }
59+ 60+ public static void breadthFirstTraversal (Vertex start , ArrayList <Vertex > visitedVertices ) {
61+ Queue visitQueue = new Queue ();
62+ visitQueue .enqueue (start );
63+ 64+ while (!visitQueue .isEmpty ()) {
65+ Vertex current = visitQueue .dequeue ();
66+ System .out .println (current .getData ());
67+ 68+ for (Edge e : current .getEdges ()) {
69+ Vertex neighbor = e .getEnd ();
70+ if (!visitedVertices .contains (neighbor )) {
71+ visitQueue .enqueue (neighbor );
72+ visitedVertices .add (neighbor );
73+ }
74+ }
75+ }
76+ }
77+ 78+ // USE IT TO TEST GRAPH
79+ class TestGraph {
80+ private Graph testGraph ;
81+ 82+ public TestGraph () {
83+ this .testGraph = new Graph (false , true );
84+ Vertex startNode = testGraph .addVertex ("v0.0.0" );
85+ Vertex v1 = this .testGraph .addVertex ("v1.0.0" );
86+ Vertex v2 = this .testGraph .addVertex ("v2.0.0" );
87+ 88+ Vertex v11 = this .testGraph .addVertex ("v1.1.0" );
89+ Vertex v12 = this .testGraph .addVertex ("v1.2.0" );
90+ Vertex v21 = this .testGraph .addVertex ("v2.1.0" );
91+ 92+ Vertex v111 = this .testGraph .addVertex ("v1.1.1" );
93+ Vertex v112 = this .testGraph .addVertex ("v1.1.2" );
94+ Vertex v121 = this .testGraph .addVertex ("v1.2.1" );
95+ Vertex v211 = this .testGraph .addVertex ("v2.1.1" );
96+ 97+ this .testGraph .addEdge (startNode , v1 , null );
98+ this .testGraph .addEdge (startNode , v2 , null );
99+ 100+ this .testGraph .addEdge (v1 , v11 , null );
101+ this .testGraph .addEdge (v1 , v12 , null );
102+ this .testGraph .addEdge (v2 , v21 , null );
103+ 104+ this .testGraph .addEdge (v11 , v111 , null );
105+ this .testGraph .addEdge (v11 , v112 , null );
106+ this .testGraph .addEdge (v12 , v121 , null );
107+ this .testGraph .addEdge (v21 , v211 , null );
108+ 109+ // create a cycle
110+ this .testGraph .addEdge (v211 , v2 , null );
111+ }
112+ 113+ public Vertex getStartingVertex () {
114+ return this .testGraph .getVertices ().get (0 );
115+ }
116+ }
117+ 118+ // MAIN METHOD
119+ public static void main (String [] args ) {
120+ TestGraph test = new TestGraph ();
121+ Vertex startingVertex = test .getStartingVertex ();
122+ ArrayList <Vertex > visitedVertices = new ArrayList <Vertex >();
123+ visitedVertices .add (startingVertex );
124+ 125+ GraphTraverser .breadthFirstTraversal (startingVertex , visitedVertices );
126+ }
127+ }}
0 commit comments