Reference no: EM131227643

Problem 1: Complete the implementation of Calculator.scala

Problem 2: Elbonia has a simple sliding scale income tax scheme. Your tax rate is determined by your income according to the following table:

Income	Rate
< $20000	0%
< $30000	5%
< $40000	11%
< $60000	23%
< $100000	32%
>= $100000	50%

Implement a tax calculator for the Elbonians: TaxCalculator.scala

Your calculator should throw an "Income can't be negative" exception if the input is negative.

Problem 3: Complete ShapeMaker.scala. Here's a sample output:

Enter a positive integer: 10

**********

**********

**********

**********

**********

**********

**********

**********

**********

**********

 

*

**

***

****

*****

******

*******

********

*********

**********

 

     *    

    ***   

   *****  

  ******* 

 *********

***********

 

***********

 *********

  ******* 

   *****  

    ***   

     *   

Problem 4: Complete VectorCalculator.scala. Additional information about arrays in Scala can be found on the web. Here, for example

Problem 5: Complete the implementation of MatrixCalculator.scala.

Here's a sample output:

Enter a positive integer: 5

 39 58 28 57 1

 77 68 99 57 85

 26 83 51 40 64

 0 55 67 57 6

 21 96 22 64 13

trace = 228

Problem 6: Rewrite the following Java method in Mystery.scala

import java.util.*;

public class Mystery {

   public static void main(String args[]) {

      Scanner kbd = new Scanner(System.in);

      System.out.print("enter a positive integer: ");

      Random r = new Random();

      int k = kbd.nextInt();

      for(inti = 0; i< 10; i++) {

         System.out.println("trial " + i);

         for(int j = 0; j < 100; j++) {

            //int k = r.nextInt(100);

            k = (k * k) % 100;

            if (k < j/3) continue;

            if (k < j/2) break;

            System.out.println("k = " + k);

         }

      }

   }

}

Hint: Use Scala's break blocks.

Problem 7: Assume the following declarations have been made:

var x = 10

lazy val y = 1 / 0

Without using Scala, what are the values (with their types) of the following expressions, if the expressions contain errors, write "error":

1. if (false) 3

2. if (false) if (true) 3 else 4     // dangling else

3. if (x = 10) true else false     

4. if (true) 1 else 1/0              // conditional eval

5. if (if (true) false else true) true else false

6. y + 10

7. println("100") // tricky!

8. true || 3 == 1/0                  // short circuit eval

9. false && (1 / 0 > 0)             // short circuit eval

Now check your answers using the Scala interpreter.

Problem 8: Assume the following declarations have been made:

var x = 10

Without using Scala, what are the values (with their types) of the following expressions, if the expressions contain errors, write "error".

1. {1; 2; 3} + {4; 5; 6}

2. {1; 2; {3; 4; {5; 6} } }

3. if (false) {2; 3} else {4; {5; 6}} + {10; 20}

4. {10; 20} + if (false) {2; 3} else {4; {5; 6}}

5. {var x = 20; var y = x + 1; x + y}

6. // { var y = x + 1; var x = 5; var z = x + 1; x + y + z}

7. {var x = 3; var y = {var x = 9; x + 1}; x + y} // shadowning

8. {def tri(n: Int): Int = if (n == 0) 0 else n + tri(n - 1); tri(5) }

// recursive blocks

Now check your answers using the Scala interpreter. Ignore the warning messages, but not the error messages.

Attachment:- Assignment.rar