detect cycle in directed by color

bool dfs(int i,bool a[],bool b[],bool c[],vector<int>adj[])
{
    a[i]=false;
    b[i]=true;
    for(auto it=adj[i].begin();it!=adj[i].end();it++)
    {
        if(b[*it])return true;
        if(a[*it]&&dfs(*it,a,b,c,adj))return true;
    }
    b[i]=false;
    c[i]=true;
    return false;
}

bool isCyclic(int V, vector<int> adj[])
{
    bool a[V]={false};
    bool b[V]={false};
    bool c[V]={false};
    for(int i=0;i<V;i++)a[i]=true;
    for(int i=0;i<V;i++)
    {
        if(a[i])
        {
            if(dfs(i,a,b,c,adj))return true;
        }
    }
    return false;
}