added breadth first search to the searching algorithms

Searching/breadth_first_search.cpp

@@ -0,0 +1,53 @@
+
+#include<bits/stdc++.h>
+using namespace std;
+void bfs(int s, vector<int> adj[], bool vis[], int N)
+{
+    queue<int>q;
+    vis[s]=1;
+    cout<<s<<" ";
+    q.push(s);
+    vector<int>::iterator i;
+    while(!q.empty()){
+        int p=q.front();
+        q.pop();
+
+        for(i=adj[p].begin();i!=adj[p].end();i++){
+            if(!vis[*i]){  //if vertex is not visited 
+                vis[*i]=1;  //mark vertex visited
+                cout<<*i<<" ";
+                q.push(*i);
+            }
+
+        }
+
+
+    }
+
+}
+int main()
+{
+
+        int N, E;//N-number of vertices and E-number of edges
+        cin>>N>>E;
+        vector<int> adj[N+1];
+        bool vis[N+1] = {false};//Mark all the vertices as not visited 
+        for(int i=0;i<E;i++)
+        {
+            int u,v;
+            cin>>u>>v;
+            adj[u].push_back(v);//creating undirected graph
+            adj[v].push_back(u);//enter vertices from 1 to N  you want to connect
+
+        }
+        int startVertex;//starting vertex from where you want to do bfs
+        cout<<"\nEnter the starting vertex from where you want to do bfs = ";
+        cin>>startVertex;
+        cout<<"\n";
+        bfs(startVertex, adj, vis, N);//printing the bfs
+        cout<<endl;
+}
+
+
+
+