Programs to check given two graphs are 1-isomorphic

#include<iostream>
#include<list>
using namespace std;

class Graph
{
  int V,E,C;
  list<int> *adj;
  public:
       Graph()
    {
       cout<<endl<<"Enter the no of vertices and edges:";
   cin>>V>>E;
   C=0;
   adj=new list<int>[V];
   
   int v1,v2;
   for(int i=0;i<E;i++)
   {
    cout<<endl<<"Enter the vertices for edge "<<i+1<<"  :";
    cin>>v1>>v2;
    adj[v1].push_back(v2);
 
    adj[v2].push_back(v1);
   }
    }
    ~Graph()
    {
     delete []adj;
    } 
       void dfs(int s,bool visited[]); 
       bool oneIsomorphism(Graph g);
       
};

void Graph::dfs(int s,bool visited[])
{
   visited[s]=true;
   list<int>::iterator it;
   for(it=adj[s].begin();it!=adj[s].end();++it)
   {
     if(!visited[*it])
       dfs(*it,visited);
   } 
   return;
}

bool Graph::oneIsomorphism(Graph g)
{
 bool *visited1=new bool[V];
 
 for(int i=0;i<V;i++)
 visited1[i]=false;
 
 for(int i=0;i<V;i++)
    if(!visited1[i])
    {
      dfs(i,visited1);
      C++;
       }
    cout<<C<<endl<<endl;
    
    bool *visited2=new bool[g.V];
    
    for(int i=0;i<g.V;i++)
 visited2[i]=false;
 
 for(int i=0;i<g.V;i++)
    if(!visited2[i])
    {
      g.dfs(i,visited2);
      g.C++;
       }
       
    int rank1=V-C;
    int rank2=g.V-g.C;
 
 cout<<rank1<<rank2<<endl;
 
 if( rank1!=rank2 )
 return false;
 
 int nullity1=E-rank1;
 int nullity2=E-rank2;
 
 cout<<nullity1<<nullity2<<endl;
 
 if( nullity1!=nullity2 )
 return false;
 
 return true; 
}

int main()
{
 Graph g1,g2;
 if(g1.oneIsomorphism(g2))
 {
  cout<<endl<<"one-isomorphic";
    }
 else
 {
     cout<<endl<<"not isomorphic";
    }
 return 0;
}