Added BFS Graph Traversal

Author: vaishnavipatil4848

Data Structures/Graphs/BFSTraversal.cpp

@@ -0,0 +1,120 @@
+/*BFS Traversal of Graph using Adjacency List 
+Representation*/
+
+#include<iostream>
+using namespace std;
+
+struct node
+{
+    node *next;
+    int vertex;
+};
+class graph
+{
+    node *G[20];
+    int visited[20];
+    int n;
+    public:
+    void create();
+    void insert(int,int);
+    void BFS_List(int);
+};
+class queue
+{
+    int data[30];
+    int r,f;
+    public:
+    queue()
+    {
+        r=f=-1;
+    }
+    int empty()
+    {
+        if(r==-1)
+        return 1;
+        return 0;
+    }
+    void insert(int x)
+    {
+        if(empty())
+        r=f=0;
+        else
+        r=r+1;
+        data[r]=x;
+    }
+    int Delete()
+    {
+        int x=data[f];
+        if(r==f)
+        r=f=-1;
+        else
+        f=f+1;
+        return x;
+    }
+};
+void graph::create()
+{
+    int i,vi,vj,e,n;
+    cout<<"\nEnter no. of vertices:";
+    cin>>n;
+    for(i=1;i<=n;i++)
+    G[i]=NULL;
+    visited[i]=0;
+    cout<<"\nEnter no. of edges:";
+    cin>>e;
+    for(i=1;i<=e;i++)
+    {
+        cout<<"\nEnter an edge:";
+        cin>>vi>>vj;
+        insert(vi,vj);
+        insert(vj,vi);
+    }
+}
+void graph::insert(int vi, int vj)
+{
+    node *p,*q;
+    q=new node;
+    q->vertex=vj;
+    q->next=NULL;
+    if(G[vi]==NULL)
+    {G[vi]=q;}
+    else 
+    {
+    p=G[vi];
+    while(p->next!=NULL)
+    {
+        p=p->next;
+    }
+    p->next=q;
+}
+}
+
+void graph::BFS_List(int v)
+{
+    int i,v2;
+    queue q;
+    node *p;
+    q.insert(v);
+    cout<<"\n Visit"<<v;
+    visited[v]=1;
+    while(!q.empty())
+    {
+        v=q.Delete();
+        for(p=G[v];p!=NULL;p=p->next)
+        {
+            v2=p->vertex;
+            if(!visited[v2])
+            {
+                q.insert(v2);
+                visited[v2]=1;
+                cout<<"\nvisit"<<v2;
+            }
+        }
+    }
+}
+int main()
+{
+    graph t;
+    t.create();
+    t.BFS_List(1);
+}