Graph using list and bfs added

Author: cs-cse

dsa-Graph/src/AdjListGraph.java

@@ -0,0 +1,66 @@
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class AdjListGraph {
+//  Undirected graph implementation using list.
+
+private LinkedList<Integer>[ ] adj;
+    private int V; // number of vertices
+    private int E; // number of edges
+
+    public AdjListGraph(int nodes) {
+        this.V = nodes;
+        this.E = 0;
+        this.adj = new LinkedList[nodes];
+        for(int v = 0; v < V; v++) {
+            adj[v] = new LinkedList<>();
+        }
+    }
+
+    public void addEdge(int u, int v) {
+        adj[u].add(v);
+        adj[v].add(u);
+        E++;
+    }
+
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(V + " vertices, " + E + " edges " + "\n");
+        for(int v = 0; v < V; v++) {
+            sb.append(v + ": ");
+            for(int w : adj[v]) {
+                sb.append(w + " ");
+            }
+            sb.append("\n");
+        }
+        return sb.toString();
+    }
+    public void bfs(int s){
+        boolean[]visited=new boolean[V];
+        Queue<Integer>q=new LinkedList<>();
+        visited[s]=true;
+        q.offer(s);
+        while (!q.isEmpty()){
+            int u=q.poll();
+            System.out.print(u+" ");
+            for(int v:adj[u]){
+                if(!visited[v]){
+                    visited[v]=true;
+                    q.offer(v);
+                }
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        AdjListGraph g = new AdjListGraph(5);
+        g.addEdge(0, 1);
+        g.addEdge(1, 2);
+        g.addEdge(2, 3);
+        g.addEdge(3, 0);
+        // 4
+        g.bfs(0);
+
+
+    }
+}