hacktoberfest-2022

BFS

@@ -0,0 +1,80 @@
+.
+#include<bits/stdc++.h>
+using namespace std;
+
+class Graph
+{
+	int V; 
+
+
+	vector<list<int>> adj;
+public:
+	Graph(int V); // Constructor
+
+	void addEdge(int v, int w);
+
+
+	void BFS(int s);
+};
+
+Graph::Graph(int V)
+{
+	this->V = V;
+	adj.resize(V);
+}
+
+void Graph::addEdge(int v, int w)
+{
+	adj[v].push_back(w); // Add w to v’s list.
+}
+
+void Graph::BFS(int s)
+{
+	// Mark all the vertices as not visited
+	vector<bool> visited;
+	visited.resize(V,false);
+
+	// Create a queue for BFS
+	list<int> queue;
+
+	// Mark the current node as visited and enqueue it
+	visited[s] = true;
+	queue.push_back(s);
+
+	while(!queue.empty())
+	{
+
+		s = queue.front();
+		cout << s << " ";
+		queue.pop_front();
+
+
+		for (auto adjecent: adj[s])
+		{
+			if (!visited[adjecent])
+			{
+				visited[adjecent] = true;
+				queue.push_back(adjecent);
+			}
+		}
+	}
+}
+
+
+int main()
+{
+
+	Graph g(4);
+	g.addEdge(0, 1);
+	g.addEdge(0, 2);
+	g.addEdge(1, 2);
+	g.addEdge(2, 0);
+	g.addEdge(2, 3);
+	g.addEdge(3, 3);
+
+	cout << "Following is Breadth First Traversal "
+		<< "(starting from vertex 2) \n";
+	g.BFS(2);
+
+	return 0;
+}