A. Assume that you are given both the preorder and postorder traversal of some binary tree t. Prove that this information, taken together, is not necessarily sufficient to reconstruct t uniquely, even if each value in t occurs only once. b. Now, assume that you have the preorder and inorder traversals of a tree (given below). Construct the corresponding binary tree and determine its postorder traversal.

Preorder Traversal: D C B A F E
Inorder Traversal: C A B D E F

This question involves a class named textfile that represents a text file. public class textfile { private string filename; private string filename; private arraylist words; // constructors not shown // postcondition: returns the number of bytes in this file public int filesize() { } // precondition: 0 < = index < words. size() // postcondition: removes numwords words from the words arraylist beginning at // index. public void deletewords(int index, int numwords) { } // precondition: 0 < = index < = words. size() // postcondition: adds elements from newwords array to words arraylist beginning // at index. pub lic voidaddwords(int index, string[] newwords) { } // other methods not shown } complete the filesize() method. the filesize() is computed in bytes. in a text file, each character in each word counts as one byte. in addition, there is a space in between each word in the words arraylist, and each of those spaces also counts as one byte. for example, suppose the words arraylist stores the following words: { mary had a little lamb; its fleece was white as snow. } the filesize() method would compute 4 + 3 + 1 + 6 + 5 + 4 + 6 + 3 + 5 + 2 + 5 as the sum of the lengths of each string in the arraylist. the value returned would be this sum plus 10, because there would also be 10 spaces in between the 11 words. complete the filesize() method below: // postcondition: returns the number of bytes in this file public int filesize() { }

22. sata3 allows for data transfer rates of 600 mb/s. explain why you would likely not be able to copy data from one hard drive to another at anywhere close to this speed. also, what could be upgraded on the computer to achieve transfer speeds closer to 600 mb/s

Using a conditional expression, write a statement that increments numusers if updatedirection is 1, otherwise decrements numusers. ex: if numusers is 8 and updatedirection is 1, numusers becomes 9; if updatedirection is 0, numusers becomes 7.