Question

java programing project

Implement a program that computes the Fibonacci of a specified number, the factorial of a specified number, or estimates the value of 'e' using the specified number of iterations (of a Taylor series). Please feel free to use the Internet to find resources that explain how to estimate the value of 'e' using a Taylor series.

In the case of no or invalid number of parameters, the program should show help instructions that looks like:

--- Assign 1 Help ---
  -fib [N] : Compute the Fibonacci of N; valid range [0, 40]
  -fac [N] : Compute the factorial of N; valid range, [0, 2147483647]
  -e [N] : Compute the value of 'e' using N iterations; valid range [1, 2147483647]

Example command-line usages of the program look like:

java Assign1 -fib 6
java Assign1 -fac 6
java Assign1 -e 24
java Assign1 -fib 6 -fac 6 -e 24
java Assign1 -fib 6 -fib 10

Example output from correct and incorrect command-line arguments:

java Assign1 -fib 6 -fib 8 -fac 10 -fac 0 -e 10 -e 100

Fibonacci of 6 is 13
Fibonacci of 8 is 34
Factorial of 10 is 3628800
Factorial of 0 is 1
Value of e using 10 iterations is 2.7182815255731922
Value of e using 100 iterations is 2.7182818284590450

java Assign1 -fib 6 -fib 50 -fac 0 -e 10 -e 0

Fibonacci of 6 is 13
Fibonacci valid range is [0, 40]
Factorial of 0 is 1
Value of e using 10 iterations is 2.7182815255731922
Valid e iterations range is [1, 2147483647]

java Assign1 -abc 123

Unknown command line argument: -abc

Your program should be able to handle any number of requested computations. Additionally, it should be able to handle the same computation request more than one time on a single command line; refer to the example command-line usages above.

Additional Notes

• Valid input ranges
  • Fibonacci input range is: 0 to 40
  • Factorial input range is: 0 to largest Java Integer
  • Iterations range for the 'e' [n] parameter is: 1 to largest Java Integer
• For computing the Fibonacci, use the sequence beginning with 1; 1, 1, 2, 3, 5, 8, ...
• Place all of your code in a single .java file named Assign1.java.
• You should use BigInteger for the factorial computation
• You should use BigDecimal for the e computation: documentation

Answer 1

//Assign1.java

import java.math.BigInteger;

import java.math.RoundingMode;

import java.math.BigDecimal;

public class Assign1 {

       public static void main(String[] args) {

             if(args.length > 0) // check the number of command line arguments

             {

                    // loop over the array of command line arguments

                    for(int i=0;i<args.length;i=i+2)

                    {

                           if(args[i].equalsIgnoreCase("-fib")) // fibonacci

                           {

                                 int n = Integer.parseInt(args[i+1]);

                                 int f1 = 1, f2 =1;

                                 if(n < 0 || n > 40)

                                        System.out.println("Fibonacci valid range is [0, 40]");

                                 else if(n < 2)

                                        System.out.println("Fibonacci of "+n+" is 1");

                                 else

                                 {

                                        int f3=0;

                                        for(int c=2;c<=n;c++)

                                        {

                                               f3 = f1+f2;

                                               f1 = f2;

                                               f2 = f3;

                                        }

                                       

                                        System.out.println("Fibonacci of "+n+" is "+f3);

                                 }

                                       

                           }else if(args[i].equalsIgnoreCase("-fac")) // factorial

                           {

                                 int n = Integer.parseInt(args[i+1]);

                                 if( n < 0)

                                 {

                                        System.out.println("Factorial valid range is [0,"+Integer.MAX_VALUE+"]");

                                 }else

                                 {

                                        BigInteger fact = new BigInteger("1");

                                        for(int c=1;c<=n;c++)

                                        {

                                               fact = fact.multiply(BigInteger.valueOf(c));

                                        }

                                       

                                        System.out.println("Factorial of "+n+" is "+fact);

                                 }

                           }else if(args[i].equals("-e")) // exp(0)

                           {

                                 int n = Integer.parseInt(args[i+1]);

                                 if(n <= 0)

                                 {

                                        System.out.println("Valid e iterations range is [1,"+Integer.MAX_VALUE+"]");

                                 }else

                                 {

                                        BigDecimal e = new BigDecimal("1");

                                       

                                        for(int c=1;c<=n;c++)

                                        {

                                               BigInteger fact = new BigInteger("1");

                                               for(int k=1;k<=c;k++)

                                                     fact = fact.multiply(BigInteger.valueOf(k));

                                               BigDecimal d = new BigDecimal(fact);

                                               e = e.add(BigDecimal.valueOf(1).divide(d,16,RoundingMode.HALF_EVEN));

                                        }

                                       

                                        System.out.println("Value of e using "+n+" iterations is "+e);

                                 }

                           }else

                                 System.out.println("Unknown command line argument: "+args[i]);

                    }

                          

             }else

             {

                    System.out.println("--- Assign 1 Help ---\r\n" +

                                 " -fib [N] : Compute the Fibonacci of N; valid range [0, 40]\r\n" +

                                 " -fac [N] : Compute the factorial of N; valid range, [0, 2147483647]\r\n" +

                                 " -e [N] : Compute the value of 'e' using N iterations; valid range [1, 2147483647]");

             }

                   

       }

}

//end of Assign1.java

Output:

java Assign1 -fib 6 -fib 8 -fac 10 -fac 0 -e 10 -e 100 -abc 123 -e 0