PROGRAM SPECIFICATION: An array that can grow and shrink (as needed) at run time is generally called a dynamic array. You are to write a class named DynArray which can hold double values that adheres to the following:

=>The physical size of the array at all times is a nonnegative power of two (smallest of which is 1). =>The physical size is never more than 2 times the number of elements which occupy it (with exception to when it is at size 1).

Mandatory Instance variables: private double[] array; private int size; private int nextIndex;

Mandatory Instance methods: public DynArray() // constructor // set array to a new array of double, of size one // set size to one, // and set nextIndex to zero.

public int arraySize() // accessor // return the value of size.

public int elements() // accessor // return the value of nextIndex.

public double at(int index) // accessor // if 0 <= index < nextIndex // return the value of array[index]. // else // return Double.NaN.

private void grow() // make array a reference to an array that is twice as large // and contains the same values for indicies 0 through // nextIndex - 1, and adjust size appropriately.

private void shrink() // make array a reference to an array that is half as large // and contains the same values for indicies 0 through // nextIndex - 1, and adjust size appropriately.

public void insertAt(int index, double value) // mutator // if 0 <= index <= nextIndex // move the nessecary values over one so that value can // be incerted at the location index in the array, inserts // incerts value at the location index, and adjust nextIndex // appropriately. // Note a grow() may be neccessary before or after. // else // do nothing.

public void insert(double value) // mutator // insert value at location nextIndex.

public double removeAt(int index) // mutator // if 0 <= index < nextIndex // move the nessecary values over one as to eliminate // the value at the location index in the array, adjust // nextIndex appropriately, and return the value that was // at the location index . // Note: a shrink() may be neccessary before or after. // else // return Double.NaN.

public double remove() // mutator // return the removal of the value at location nextIndex-1.

public void printArray() //accessor // prints the values of all occupied locations of the array to // the screen

DRIVER CLASS:

public class DynArrayDriver { public static void main(String[] args) { DynArray myArray = new DynArray();

System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements()); System.out.println(" ");

int pot = 1; for (int v = 0; v < 10; ++v) { myArray.insert(pot); System.out.println("myArray.at(" + v + ") = " + myArray.at(v)); System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements() + " "); pot *= 2; } System.out.println("myArray.at(10) = " + myArray.at(10)); System.out.println(" ");

for (int v = 0; v < 10; ++v) { double value = myArray.remove(); System.out.println("value = " + value); System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements() + " "); } double value = myArray.remove(); System.out.println("value = " + value); System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements()); System.out.println(" ");

for (int i = 0; i < 5; ++i) { myArray.insertAt(i, 3 * i); System.out.println("myArray.at(" + i + ") = " + myArray.at(i)); System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements() + " "); } myArray.printArray(); System.out.println();

value = myArray.removeAt(2); System.out.println("value = " + value); System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements() + " "); myArray.printArray(); System.out.println();

value = myArray.removeAt(4); System.out.println("value = " + value); System.out.println("size = " + myArray.arraySize()); System.out.println("elements = " + myArray.elements() + " "); } }

COMPILED CODE:

size = 1 elements = 0

myArray.at(0) = 1.0 size = 1 elements = 1

myArray.at(1) = 2.0 size = 2 elements = 2

myArray.at(2) = 4.0 size = 4 elements = 3

myArray.at(3) = 8.0 size = 4 elements = 4

myArray.at(4) = 16.0 size = 8 elements = 5

myArray.at(5) = 32.0 size = 8 elements = 6

myArray.at(6) = 64.0 size = 8 elements = 7

myArray.at(7) = 128.0 size = 8 elements = 8

myArray.at(8) = 256.0 size = 16 elements = 9

myArray.at(9) = 512.0 size = 16 elements = 10

myArray.at(10) = NaN

value = 512.0 size = 16 elements = 9

value = 256.0 size = 16 elements = 8

value = 128.0 size = 8 elements = 7

value = 64.0 size = 8 elements = 6

value = 32.0 size = 8 elements = 5

value = 16.0 size = 8 elements = 4

value = 8.0 size = 4 elements = 3

value = 4.0 size = 4 elements = 2

value = 2.0 size = 2 elements = 1

value = 1.0 size = 1 elements = 0

value = NaN size = 1 elements = 0

myArray.at(0) = 0.0 size = 1 elements = 1

myArray.at(1) = 3.0 size = 2 elements = 2

myArray.at(2) = 6.0 size = 4 elements = 3

myArray.at(3) = 9.0 size = 4 elements = 4

myArray.at(4) = 12.0 size = 8 elements = 5

array.at(0) = 0.0 array.at(1) = 3.0 array.at(2) = 6.0 array.at(3) = 9.0 array.at(4) = 12.0

value = 6.0 size = 8 elements = 4

array.at(0) = 0.0 array.at(1) = 3.0 array.at(2) = 9.0 array.at(3) = 12.0

value = NaN size = 8 elements = 4