Cycle in directed graph

//Link to the question : https://practice.geeksforgeeks.org/problems/detect-cycle-in-a-directed-graph/1#

bool check(vector<int> adj[],vector<int> &visit, int curr, int rank){

    visit[curr] =rank;
    rank++;

    for(int i = 0; i< adj[curr].size(); i++){
        int ncurr =  adj[curr][i];
        if(visit[ncurr]==-1){
            if(check(adj,visit,ncurr,rank)==true)return true;
        }
        else{
            if(visit[ncurr]<rank)return true;
        }
    }

    visit[curr] = visit.size()+1;

    return false;

}

class Solution
{
    public:
	//Function to detect cycle in a directed graph.
	bool isCyclic(int V, vector<int> adj[])
	{
	   	// code here
	   	vector<int>visit(V,-1);

	   	for(int i = 0; i<V; i++){
	   	    if(visit[i]==-1){
	   	        if(check(adj,visit,i,0)==true)return true;
	   	    }
	   	}

	   	return false;

	}
};