/*
 * Illustrates some advanced array concepts
 */

#include <iostream>
using namespace std;

void single_pointer(int *arg) {
	cout << "\t Inside function single_pointer:" << endl;
	cout << "\t\t  int * = " << arg << endl;
	cout << "\t\t  int   = " << *arg << endl;

	int SIZE = 5;
	int *new_array = new int[SIZE];
	for(int i = 0; i < SIZE; i++) {
		new_array[i] = 47;
	}
	arg = new_array;

	cout << "\t Inside function single_pointer:" << endl;
	cout << "\t\t  int * = " << arg << endl;
	cout << "\t\t  int   = " << *arg << endl;
}

void double_pointer(int **arg) {
	cout << "\t Inside function double_pointer:" << endl;
	cout << "\t\t int ** = " << arg << endl;
	cout << "\t\t int *  = " << *arg << endl;
	cout << "\t\t int    = " << **arg << endl;

	int SIZE = 5;
	int * new_array = new int[SIZE];
	for(int i = 0; i < SIZE; i++) {
		new_array[i] = 14; // Prof. Chambers' favorite number!
	}
	(*arg) = new_array;

	cout << "\t Inside function double_pointer:" << endl;
	cout << "\t\t int ** = " << arg << endl;
	cout << "\t\t int *  = " << *arg << endl;
	cout << "\t\t int    = " << **arg << endl;
}


int main() {
	int SIZE = 5;

	/******************************************************
	 * Lesson One: Constant pointers cannot be reassigned *
	 ******************************************************/
	int array1[SIZE];
	int array2[SIZE];
	// array1 = array2;


	/**************************************************************************
	 * Lesson Two: Array names are converted to a pointer except in two cases *
	 **************************************************************************/

	// When an array is used in an expression, it is converted to the address of the first element
	*(array1+0) = 3;
	*(array1+1) = 3;
	*(array1+2) = 3;
	*(array1+3) = 3;
	*(array1+4) = 3;


	// The two exceptions are the sizeof operator and the addressof (&) operator
	// In these two cases, the array name refers to the entire array of N elements
	cout << "Number of bytes for *entire* array: " << sizeof(array1) <<  " bytes" << endl;
	cout << "Address of first element: " << array1 << endl;
	cout << "Address of entire array: " << &array1 << endl;
	cout << endl << endl;


	/*******************************************************************
	 * Lesson Three: Dynamically allocated arrays are always pointers  *
	 *******************************************************************/

	// array3 is a true pointer
	int *array3 = new int[SIZE];

	cout << "Address in main: " << array3 << endl;
	single_pointer(array3);
	cout << "Address in main: " << array3 << endl;
	cout << endl << endl;


	cout << "Address in main: " << array3 << endl;
	double_pointer(&array3);
	cout << "Address in main: " << array3 << endl;
	cout << endl << endl;


	return 0;
}