3. Give a non-recursive algorithm that performs an inorder tree walk for a tree containing n nodes. The algorithm should run in O(n) time. [6 marks) 4. What is the largest possible number of internal nodes in a red-black tree with black height k? What is the smallest possible number? [5 marks] 5. Show that red-black BSTs are not memoryless: for example, if you insert a key that is smaller than all the keys in the tree and then immediately delete the minimum, you may get a different tree. [7 marks)