(6) (a) Calculate the result of postfix expression: (0.5 point) 9 3 6 /4 10 - (b) How does the AVL (Adelson-Velski and Landis, organizing a Balanced BST to guarantee good performance. (0.5 point) (c) What was the idea of Huffman coding to reduce the overall (0.5 point) size of the file (7) (a) The big o function for searching an element in a search tree is: (0.5 point) Where n is the height of the tree A. O(n) B. O (logn) c. O(nlogn) D. O(n 2)