Added code

Author: ShashankSinha98

33. Graph 02/BFS_Traversal_Graph.java

@@ -0,0 +1,75 @@
+import java.util.*;
+
+class GraphBFS{
+	
+	Map<Object,ArrayList<Object>> map;
+	
+	GraphBFS(){
+		this.map = new HashMap<>();
+	}
+	
+	public void add_edge(Object v1, Object v2) {
+		
+		ArrayList<Object> list;
+		
+		if(map.containsKey(v1))
+			list = map.get(v1);
+		else
+			list = new ArrayList<>();
+		list.add(v2);
+		this.map.put(v1, list);
+		
+		if(map.containsKey(v2))
+			list = map.get(v2);
+		else
+			list = new ArrayList<>();
+		list.add(v1);
+		this.map.put(v2, list);
+	}
+	
+	public void bfs(Object src) {
+		Queue<Object> q = new LinkedList<>();
+		Map<Object,Boolean> visited = new HashMap<>();
+		
+		q.add(src);
+		visited.put(src, true);
+		
+		
+		while(!q.isEmpty()) {
+			//System.out.println(q);
+			Object curr_item = q.remove();
+			System.out.println(curr_item);
+			
+			ArrayList<Object> list = this.map.get(curr_item);
+			
+			for(Object o : list) {
+				if(!visited.containsKey(o) || !visited.get(o)) {
+					q.add(o);
+					visited.put(o, true);
+				}
+			}
+		}
+		
+	}
+	
+}
+
+public class BFS_Traversal_Graph {
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+		
+		GraphBFS g = new GraphBFS();
+		
+		g.add_edge(0, 1);
+		g.add_edge(0, 3);
+		g.add_edge(1, 2);
+		g.add_edge(2, 3);
+		g.add_edge(3, 4);
+		g.add_edge(4, 5);
+		
+		g.bfs(0);
+
+	}
+
+}