package algorithm.graph;
import java.util.LinkedList;
import java.util.Queue;
/**
* The type Bfs.
*/
public class BFS {
/**
* Bfs string.
*
* @param graph the graph
* @return the string
*/
public static String bfs(Graph graph) {
int vertices = graph.getVertices();
boolean[] visited = new boolean[vertices];
String result = "";
for (int i = 0; i < vertices; i++) {
if (!visited[i]) {
result += vistGraph(graph, i, visited);
}
}
return result;
}
private static String vistGraph(Graph graph, int source, boolean[] visited) {
String result = "";
Queue queue = new LinkedList<>();
queue.add(source);
visited[source] = true;
while (!queue.isEmpty()) {
int currentNod = queue.remove();
result += String.valueOf(currentNod);
LinkedList temp = null;
if (graph.getAdj()[source] != null) {
temp = graph.getAdj()[source];
}
for (int i = 0; i < temp.size(); i++) {
if (!visited[temp.get(i)]) {
queue.add(temp.get(i));
visited[temp.get(i)] = true;
}
}
}
return result;
}
/**
* Main.
*
* @param args the args
*/
public static void main(String args[]) {
Graph g = new Graph(5);
g.addEdge(0, 1);
g.addEdge(0, 2);
g.addEdge(1, 3);
g.addEdge(1, 4);
System.out.println("Graph1:");
g.printGraph();
System.out.println("BFS traversal of Graph1 : " + bfs(g));
System.out.println();
Graph g2 = new Graph(5);
g2.addEdge(0, 1);
g2.addEdge(0, 4);
g2.addEdge(1, 2);
g2.addEdge(3, 4);
System.out.println("Graph2:");
g2.printGraph();
System.out.println("BFS traversal of Graph2 : " + bfs(g2));
}
}