solve hw-9

hws/tiktok_trends/StringInterner.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <string>
+#include <unordered_set>
+#include <utility>
+
+class StringInterner {
+private:
+    std::unordered_set<std::string> pool;
+
+public:
+    const std::string* intern(const std::string& str);
+    const std::string* intern(std::string&& str);
+    const std::string* getEmptyString();
+};