11.md

Cycle Detection in Directed Graph

bool dfs(int i,vector<int> adj[],vector<int>&visited,vector<int>&path)
    {
        visited[i]=1;
        path[i]=1;
        
        for(auto it: adj[i])
        {
            if(!visited[it])
            {
                if(dfs(it,adj,visited,path)==true)
                    return true;
            }
                    
            else if(path[it]==1)
                return true;
        }
        path[i]=0;
        return false;
    }
    bool isCyclic(int V, vector<int> adj[]) {
        // code here
        
        vector<int>visited(V,0);
        vector<int>path(V,0);
        
        for(int i=0;i<V;i++)
        {
            if(!visited[i])
                if(dfs(i,adj,visited,path)==true)
                    return true;
        }
        
        return false;
    }