class Solution

{

    //Function to detect cycle using DSU in an undirected graph.

    public int detectCycle(int V, ArrayList<ArrayList<Integer>> adj)

    {

        int[] parent=new int[V];

        int[] rank=new int[V];

        for(int i=0;i<V;i++){

            parent[i]=i;

            rank[i]=1;

        }

        for(int i=0;i<V;i++){

            for(int j:adj.get(i)){

                if(i<j&&union(i,j,parent,rank,V)){

                    return 1;

                }

            }

        }

        return 0;

    }

    public boolean union(int i,int j,int[] parent,int[] rank,int n){

        i=find(i,parent);

        j=find(j,parent);

        if(i==j) return true;  //cycle exists(they are already connected)

        if(rank[i]>rank[j]){

            parent[j]=i;

        }

        else if(rank[j]>rank[i]){

            parent[i]=j;

        }

        else{

            parent[j]=i;

            rank[i]+=1;

        }

        return false;

    }

    public int find(int v,int[] parent){

        if(v==parent[v]) return v;

        return parent[v]=find(parent[v],parent);

    }

}