Homework Assignment #1 Solution

Description

Instructions: Please submit on Canvas.

Problem 1 [6pts]. Determine the answer to the following expressions. You must provide a short explanation (a sentence of two) for each one.

• 2 % 3

• 0 % 3

• 3 % 3

• -2%3

• 2%-3

• -2%-3

Submission format: A text file problem1.txt.

Problem 2 [5pts]. We all know about bits and bytes. In particular we know that 1 byte equals 23 = 8 bits. Now, you might have noticed that a hard disk drive which is advertised as having a capacity equal to 500 Gigabytes, shows up in your operating system with a smaller number, approximately 465. Why is that? It is because, in marketing, the SI¹ units are used where 1Kilo = 103 = 1000. On the other hand, in computer science we use the IEC² standard where 1Kilo = 210 = 1024. To avoid confusion, when working with powers of 2, we are supposed to write KiB instead of KB (i.e. kibi instead of kilo) and so on.³ For example

1MB = 1000KB = 1000 1000B = 10⁶B

1MiB = 1024KiB = 1024 1024B = 2²⁰B

In this problem, you write a simple program that coverts giga to gibi. For example, given 500GB as input you must calculate its equivalence in GiB. Below is a skeleton for the code

¹Systèm Internationale

²International Electrotechnical Commission

³Read https://en.wikipedia.org/wiki/biary_prefix

public class Converter {

public static void main(String[] args) { long giga = 500;

long gibi = 0;

• your code for computing gibi from giga System.out.println(giga + “GB = ” + gibi + “GiB”);

}

}

Submission format: A java source file Converter.java.

Problem 3 [4pts]. The following program will compile and run, but it uses a poor pro-gramming style. Modify the code so that it uses the coding conventions described in the class and mentioned in the book.

public class mess {

public static void main(String[] args)

{

double TIME; double PACE;

System.out.println(“This program calculates pace”);

TIME = 35.5; /* 35 minutes and 30 seconds */

PACE = TIME / distance;

System.out.println(“Pace is ” + PACE + ” miles per hour.”); double distance = 6.21;

}

}

Refer to §1.4 (Program Style) in your book or consult the slides. Submission format: A Java source file with the correct name and extension.

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