Answer57.cpp

#include<unordered_map>
#include<list>

void dfs(int node, unordered_map <int, list<int> > & adj, unordered_map<int,bool> & visited, vector<int> & component){
    component.push_back(node);
    visited[node] = true;
    
    for(auto i:adj[node]){
        if( !visited[i] ){
        dfs(i,adj,visited,component);
    }
    
  }
}
vector<vector<int>> depthFirstSearch(int V, int E, vector<vector<int>> &edges)
{
    // prepare of adjacent list
    
    unordered_map <int, list<int> > adj;
    for (int i=0; i < edges.size(); i++)
    {
        
        int u = edges[i][0];
        int v = edges[i][1];
        
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    
       //ans 
        vector<vector<int>> ans;
        //visited having i th node and bool 
        unordered_map <int,bool > visited;
        
        for(int i=0;i<V;i++){
            if(!visited[i]){
                vector<int>component;
                dfs(i,adj,visited ,component);
                ans.push_back(component);
            }
    }
    return ans;
    };