Question

PART 1

Modify the class ArrayList given in Exercise 1 by using expandable arrays. That is, if the list is full when an item is being added to this list, the elements will be moved to a larger array. The new array should have twice the size of the original array. Using the new class ArrayList, write a program to store 1,000 random numbers, each in the interval [0, 500]. The initial size of the array in the class should be set to 100. Print the numbers

/******************************
* Week 1 lab - exercise 1:   *
*   a simple ArrayList class *
*******************************/

#include
#include "ArrayList.h"

using namespace std;

/*
* Default constructor. Sets length to 0, initializing the list as an empty
* list. Default size of array is 20.
*/
ArrayList::ArrayList()
{
   SIZE = 20;
   list = new int[SIZE];
   length = 0;
}

/*
* Destructor. Deallocates the dynamic array list.
*/
ArrayList::~ArrayList()
{
   delete [] list;
   list = NULL;
}

/*
* Determines whether the list is empty.
*
* Returns true if the list is empty, false otherwise.
*/
bool ArrayList::isEmpty()
{
   return length == 0;
}

/*
* Prints the list elements.
*/
void ArrayList::display()
{
   for (int i=0; i < length; i++)
       cout << list[i] << " ";
   cout << endl;
}

/*
* Adds the element x to the end of the list. List length is increased by 1.
*
* x: element to be added to the list
*/
void ArrayList::add(int x)
{
   if (length == SIZE)
   {
       cout << "Insertion Error: list is full" << endl;
   }
   else
   {
       list[length] = x;
       length++;
   }
}

/*
* Removes the element at the given location from the list. List length is
* decreased by 1.
*
* pos: location of the item to be removed
*/
void ArrayList::removeAt(int pos)
{
   if (pos < 0 || pos >= length)
   {
       cout << "Removal Error: invalid position" << endl;
   }
   else
   {
       for ( int i = pos; i < length - 1; i++ )
           list[i] = list[i+1];
       length--;
   }
}

PART 2

Create a class Bag (multiset) that uses an expandable array to store the bag items. The item type must be int. The class should have the methods listed below. Create a main class to test your bag class. This main class should fill a bag of integers with 10 random numbers, each in the interval [0, 20], and print how many times each integer in the interval [0, 20] appears in the bag.

1. Bag(): default constructor
2. bool isEmpty(): determines whether the bag is empty
3. void print(): prints the bag elements
4. int getLength(): returns the number of items in the bag
5. void clear(): removes all of the items from the bag
6. void add(int item): adds an item to the bag
7. void remove(int item): removes item from the bag; only one occurrence of item should be removed.
8. int count(int item): counts the number of occurrences of item in the bag.

PART 3

Write a program that fills a vector object with the keywords of the C++ language. Once filled, the vector elements should be displayed.

Answer 1

Part 1:

Program screenshot: