Update copy-list-with-random-pointer.cpp as in the video

Problem: 0138-copy-list-with-random-pointer.cpp
Language: C++
Submission: https://leetcode.com/problems/copy-list-with-random-pointer/submissions/875731269/

Author: caba5

Diff for: cpp/0138-copy-list-with-random-pointer.cpp

@@ -55,7 +55,7 @@ class Node {
 //         return visited[node];
 //     }
 // };
-
+/*
 class Solution {
 public:
     Node* copyRandomList(Node* head) {
@@ -99,3 +99,25 @@ class Solution {
         return oldHead;
     }
 };
+*/
+
+class Solution {
+public:
+    Node* copyRandomList(Node* head) {
+        unordered_map<Node*, Node*> nodes;
+        Node* h = head;
+        
+        while (h){
+            nodes[h] = new Node(h->val);
+            h = h->next;
+        }
+        h = head;
+        while (h){
+            Node* newNode = nodes[h];
+            newNode->next = nodes[h->next];
+            newNode->random = nodes[h->random];
+            h = h->next;
+        }
+        return nodes[head];
+    }
+};