Question

Create a class that allows you to treat the 10 separate arrays in Exercise 10 as a single

one-dimensional array, using array notation with a single index. That is, statements in

main() can access their elements using expressions like a[j], even though the class

member functions must access the data using the two-step approach. Overload the subscript

operator [] (see Chapter 9, “Inheritance”) to achieve this result. Fill the arrays

with test data and then display it. Although array notation is used in the class interface in

main() to access “array” elements, you should use only pointer notation for all the operations

in the implementation (within the class member functions).

Answer 1

#include <cstdlib>
#include <iostream>


using namespace std;


class Arr10 {


public:
	static const size_t 	TOTAL_ARRAYS = 10;
	Arr10(size_t _size);
	~Arr10();
	int& operator[](int);
	void print() const;
private:
	int * 				arr[TOTAL_ARRAYS];
	size_t 				size;
};


int& Arr10::operator[](int index)
{
	if (static_cast<size_t>(index) >= size * TOTAL_ARRAYS) {
		return arr[0][0];
	}
	size_t x = index / size;
	size_t y = index % size;
	return arr[x][y];
}


Arr10::Arr10(size_t _size)
{
	size = _size;


	if (size != 0) {
		for (int i = 0; i < static_cast<int>(TOTAL_ARRAYS); ++i) {
			arr[i] = new int[size];
			for (int j = 0; j < static_cast<int>(size); ++j) {
				arr[i][j] = 0;
			}
		}
	}
}


Arr10::~Arr10()
{
	for (int i = 0; i < static_cast<int>(TOTAL_ARRAYS); ++i) {
		for (int j = 0; j < static_cast<int>(size); ++j) {
			delete arr[i];
		}
	}
}


void Arr10::print() const
{
	for (int i = 0; i < static_cast<int>(TOTAL_ARRAYS); ++i) {
		for (int j = 0; j < static_cast<int>(size); ++j) {
			cout << arr[i][j] << " ";
		}
		cout << endl;
	}




}


int main()
{
	size_t s = 4;
	Arr10 arr10(s);
	for (int i = 0; i < static_cast<int>(s * Arr10::TOTAL_ARRAYS); ++i)
		arr10[i] = i;


	arr10.print();


	arr10[0] = 66;
	arr10[4] = 66;
	arr10[8] = 66;
	arr10[33333] = 66;
	cout << endl;
	arr10.print();
	return 0;
}