Set - 7

Question 21 :

What is the difference between a Java application and a Java applet? 

Answer :

The difference between a Java application and a Java applet is that a Java application is a program that can be executed using the Java interpeter, and a JAVA applet can be transfered to different networks and executed by using a web browser (transferable to the WWW).


Question 22 :

Name 7 layers of the OSI Reference Model?

Answer :

-Application layer
-Presentation layer
-Session layer
-Transport layer
-Network layer
-Data Link layer
-Physical layer


Question 23 :

What are the advantages and disadvantages of B-star trees over Binary trees?

Answer :

Answer1
B-star trees have better data structure and are faster in search than Binary trees, but it's harder to write codes for B-start trees. 

Answer2
The major difference between B-tree and binary tres is that B-tree is a external data structure and binary tree is a main memory data structure. The computational complexity of binary tree is counted by the number of comparison operations at each node, while the computational complexity of B-tree is determined by the disk I/O, that is, the number of node that will be loaded from disk to main memory. The comparision of the different values in one node is not counted.


Question 24 :

Write the psuedo code for the Depth first Search?

Answer :

dfs(G, v) //OUTLINE
Mark v as "discovered"
For each vertex w such that edge vw is in G:
If w is undiscovered:
dfs(G, w); that is, explore vw, visit w, explore from there as much as possible, and backtrack from w to v. Otherwise:
"Check" vw without visiting w. Mark v as "finished".


Question 25 :

Describe one simple rehashing policy?

Answer :

The simplest rehashing policy is linear probing. Suppose a key K hashes to location i. Suppose other key occupies H[i]. The following function is used to generate alternative locations: 
rehash(j) = (j + 1) mod h 
where j is the location most recently probed. Initially j = i, the hash code for K. Notice that this version of rehash does not depend on K.