From c112fc9845b4fd8d91a0fc6ab27e63f9032c0a3b Mon Sep 17 00:00:00 2001
From: nileshtadha5 <44526348+nileshtadha5@users.noreply.github.com>
Date: Sat, 27 Oct 2018 19:11:42 +0530
Subject: [PATCH] Create bfs
---
bfs | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
create mode 100644 bfs
diff --git a/bfs b/bfs
new file mode 100644
index 0000000000..6afb0788da
--- /dev/null
+++ b/bfs
@@ -0,0 +1,92 @@
+#include<iostream>
+#include <list>
+
+using namespace std;
+
+// This class represents a directed graph using
+// adjacency list representation
+class Graph
+{
+ int V; // No. of vertices
+
+ // Pointer to an array containing adjacency
+ // lists
+ list<int> *adj;
+public:
+ Graph(int V); // Constructor
+
+ // function to add an edge to graph
+ void addEdge(int v, int w);
+
+ // prints BFS traversal from a given source s
+ void BFS(int s);
+};
+
+Graph::Graph(int V)
+{
+ this->V = V;
+ adj = new list<int>[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
+ bool *visited = new bool[V];
+ for(int i = 0; i < V; i++)
+ visited[i] = 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);
+
+ // 'i' will be used to get all adjacent
+ // vertices of a vertex
+ list<int>::iterator i;
+
+ while(!queue.empty())
+ {
+ // Dequeue a vertex from queue and print it
+ s = queue.front();
+ cout << s << " ";
+ queue.pop_front();
+
+ // Get all adjacent vertices of the dequeued
+ // vertex s. If a adjacent has not been visited,
+ // then mark it visited and enqueue it
+ for (i = adj[s].begin(); i != adj[s].end(); ++i)
+ {
+ if (!visited[*i])
+ {
+ visited[*i] = true;
+ queue.push_back(*i);
+ }
+ }
+ }
+}
+
+// Driver program to test methods of graph class
+int main()
+{
+ // Create a graph given in the above diagram
+ 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;
+}