Graphs

Implement BFS algorithm in a directed graph

BFS.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+//Time Complexity O(V+E)
+vector<int>bfsOfGraph(int v, vector<int> adj[])
+{
+	vector<int>bfs;
+	vector<int>vis(v,0);
+	queue<int>q;
+	q.push(0);//pushing first node in queue
+    vis[0]=1; //marking it traversed
+	while(!q.empty())
+    {
+	    int node=q.front();
+	    q.pop();
+        bfs.push_back(node);//putting the node in bfs
+        for(auto i:adj[node]) //checking adjacent nodes of the bfs
+	    {
+	        if(vis[i]==0)
+	        {
+	            q.push(i); //pushing adjacent nodes
+	            vis[i]=1; //marking it
+	        }
+	    }
+	}
+	return bfs;
+}
+int main()
+{
+    int V, E;
+    cin >> V >> E;
+
+    vector<int> adj[V];
+
+    for(int i = 0; i < E; i++)
+    {
+    	int u, v;
+    	cin >> u >> v;
+    	adj[u].push_back(v);
+        //adj[v].push_back(u); here graph is directed
+    }
+    vector<int>ans = bfsOfGraph(V, adj);
+    for(int i=0;i<ans.size();i++)
+    {
+        cout<<ans[i]<<" ";
+    }
+        cout<<endl;
+    return 0;
+}