add header file for set

Assignment_2/lib/Set.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "Node.h"
+
+class Set {
+    protected:
+        std::string name;
+        Set(std::string _name);
+        Node* first;
+    public:
+        bool add(int element);
+        bool rmv(int element);
+        bool ctn(int element);
+        std::string get_name();
+};