Computer Science, Paper I

(a) Write a program that prompts the user to enter a letter grade A, B, C, D, or F and displays its corresponding numeric value 4, 3, 2, 1, or 0.

(b) Write pseudocode OR C-language script for the following expression.

$$\vec{a} \cdot \vec{b} = \sum_{i=1}^{n} a_i b_i = a_1 b_1 + a_2 b_2 + \ldots + a_n b_n$$

(c) Write a version of Breadth First Search (BFS) that finds the distances from the start node to each of the others, rather than the actual paths.

(a) Show the output of the following code?

public class Test {

public static void main(String[] args) {

Double x = 3.5;

System.out.println(x.intValue());

System.out.println(x.compareTo(4.5));

}

}

(b) Illustrate the difference between overriding and overloading by the piece of pseudocode or program.

(c) How do you prevent a class from being extended? How do you prevent a method from being overridden? Exemplify with simple piece of code.

Write Regular Expression(s) for the following: