Create copy_list_with_random_ptr.cpp

Author: avidLearnerInProgress

copy_list_with_random_ptr.cpp

@@ -0,0 +1,39 @@
+/*
+// Definition for a Node.
+class Node {
+public:
+    int val;
+    Node* next;
+    Node* random;
+    
+    Node(int _val) {
+        val = _val;
+        next = NULL;
+        random = NULL;
+    }
+};
+*/
+
+class Solution {
+public:
+    Node* copyRandomList(Node* head) {
+        
+        auto current_node = head;
+        map<Node*, Node*> mp;
+        
+        //step 1: copy nodes
+        while(current_node) {
+            mp[current_node] = new Node(current_node->val);
+            current_node = current_node->next;
+        }
+        
+        //step 2: fix random and next pointers
+        current_node = head;
+        while(current_node) {
+            mp[current_node]->next  = mp[current_node->next];
+            mp[current_node]->random = mp[current_node->random];
+            current_node = current_node->next;
+        }
+        return mp[head];
+    }
+};