1. Assume I have a singly-linked list which contains a sentinel header, sentinel trailer, and a number of additional meaningful nodes. The sentinel header has an elem value of-1 and the sentinel trailer has an elem value of 999. The meaningful nodes are not in any particular order. Write the C++ searchList function which will searclh for the node whose elem value is 300. If it is not found, stop at the sentinel trailer. The nodes were built using the following classes: Class dataNodet Private: Int elem; dataNode *next; friend class LinkedList; class LinkedList public: LinkedList ; LinkedList Const int & searchList) const; Void addNode (int&e Private: dataNode* head; )