clone_graph.cpp

// Problem Link : https://leetcode.com/problems/clone-graph/description/

 void dfs(Node *node , Node *copy , vector<Node *>&vis){
        vis[copy->val]= copy ; 
        for(auto x : node->neighbors){
            if(vis[x->val]==NULL){
                Node *newNode = new Node(x->val) ; 
                (copy->neighbors).push_back(newNode) ; 
                dfs(x , newNode , vis) ; 
            }

            else {
                (copy->neighbors).push_back(vis[x->val]);
            }

        }
    }
    Node* cloneGraph(Node* node) {
         if(node==NULL){
             return node ; 
         }

         vector<Node *>vis(1000 , NULL) ; 
         Node *copy = new Node(node->val) ; 
         dfs(node , copy , vis) ; 
         return copy ; 
    }