Detecting a cycle in a directed graph using Depth First Traversal

#include <iostream>
#include <list>
using namespace std;
#define NUM_V 4
bool helper(list<int> *graph, int u, bool* visited, bool* recStack)
{
  visited[u]=true;
  recStack[u]=true;
  list<int>::iterator i;
  for(i = graph[u].begin();i!=graph[u].end();++i){
    if(recStack[*i]) //if vertice v is found in recursion stack of this DFS traversal
      return true;
    else if(*i==u) //if there's an edge from the vertex to itself
      return true;
    else if(!visited[*i]){
      if(helper(graph, *i, visited, recStack))
      return true;
    }
  }
  recStack[u]=false;
return false;
}
/*
/The wrapper function calls helper function on each vertices which have not been visited. Helper
function returns true if it detects a back edge in the subgraph(tree) or false.
*/
bool isCyclic(list<int> *graph, int V)
{
  bool visited[V]; //array to track vertices already visited
  bool recStack[V]; //array to track vertices in recursion stack of the traversal.
  for(int i = 0;i<V;i++)
    visited[i]=false, recStack[i]=false; //initialize all vertices as not visited and not recursed
  for(int u = 0; u < V; u++) //Iteratively checks if every vertices have been visited
  {
    if(visited[u]==false)
    {
      if(helper(graph, u, visited, recStack)) //checks if the DFS tree from the vertex contains a cycle
        return true;
    }
  }
  return false;
}

/*
Driver function
*/
int main()
{
  list<int>* graph = new list<int>[NUM_V];
  graph[0].push_back(1);
  graph[0].push_back(2);
  graph[1].push_back(2);
  graph[2].push_back(0);
  graph[2].push_back(3);
  graph[3].push_back(3);
  bool res = isCyclic(graph, NUM_V);
  cout<<res<<endl;
}