Program to print all elementary cycles in a directed graph

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

int circle[100];
int k=0;

class Graph
{
    int V,E;
 list<int> *adj;
 public:
  Graph()
  {
   cout<<endl<<"Enter the no of vertices and edges:";
   cin>>V>>E;
   
   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);
   }
  }
  ~Graph()
  {
   delete []adj;
  }
  void isCycle();
  void isCyclicUtil(int v,bool visited[],bool rec[]);   
    
};

void Graph::isCyclicUtil(int v,bool visited[],bool rec[])
{
     if(!visited[v])
  {
          visited[v]=true;   
     rec[v]=true;
     
     circle[k++]=v;
     
     list<int>::iterator it;
     for(it=adj[v].begin();it!=adj[v].end();++it)
     {
         if( !visited[*it] )
     {
      isCyclicUtil(*it,visited,rec);
     } 
        else
        if(rec[*it])
        {
         for(int i=0;i<k;i++)
         cout<<circle[i]<<" ";
         cout<<endl;
        }
      
     }
        rec[v]=false;
    visited[v]=false;
    k--;
  } 
 
}

void Graph::isCycle()
{
 bool *visited=new bool[V];
 bool *rec=new bool[V];
 
 for(int i=0;i<V;i++)
 {
  visited[i]=false;
  rec[i]=false;
 }
    isCyclicUtil(0,visited,rec);
 
}


int main()
{
 Graph g;
  cout<<"All possible Cycles :"<<endl;
 g.isCycle();

 return 0;
}