Copy List With Random Pointer: hahsmap, recursion.

Author: DeanChensj

Hard/138_Copy-List-with-Random-Pointer.cpp

@@ -0,0 +1,14 @@
+#include "../Header.h"
+
+using namespace std;
+
+RandomListNode *copyRandomList(RandomListNode *head) {
+    if (!head) return nullptr;
+    // new node finded
+    if (hash.find(head) == hash.end()) {
+        hash[head] = new RandomListNode(head->label);
+        hash[head]->random = copyRandomList(head->random);
+        hash[head]->next = copyRandomList(head->next);
+    }
+    return hash[head];
+}