3. Draw the recursion tree when n = 12, where n represents the length of the array, for the following recursive method: int sumSquares (int[] array, int first, int last) ( if (first == last) return array [first] * array[first]; int mid (first + last) / 2; return sumSquares (array, first, mid) + sumSquares (array, mid + 1, last); } • Determine a formula that counts the numbers of nodes in the recursion tree. What is the Big-Ⓒ for execution time? • Determine a formula that expresses the height of the tree. What is the Big-Ⓒ for memory? • Write an iterative solution for this same problem and compare its efficiency with this recursive solution.

Problem 2: Create a ticket spin lock Complete the functions in ticket_spin_lock.cpp to implement a ticket lock that spins while waiting. Some useful hints: • The lock_t* lock struct containts the variables int ticket and int turn. • Use the atomic function_sync_fetch_and_add( int* ticket, int addition ). This function will atomically fetch the value in ticket and add addition to this value. • You may not need to do anything in the destroy function.

MATLAB. write code for all parts