#include<iostream>

using std::cout;
using std::endl;

int main()
{
	int N{100};       // Initializing variable for size of array

	int *v;            // Declaring a pointer to the integer array

	v = new int [N+1];    // Allocating memory of size N+1

	int arraySizeBytes{0};    // Total size of the array in bytes

	int elementSizeBytes{0};    // Size of an individual element in bytes

	int counter{0};    // Number of elements in the array
	
	v[1] = 7; v[2] = -3; v[3] = 1;    // Initialize and store value in elements of array

    cout << "Values stored in the array:" << endl;

	for (int i = 0; 1 < N; i++)
	{
		if(v[i] != 0)
		{
			cout << v[i] << "\n";    // Print value of each element in the array
		}
	}


	delete [] v;        // Free up memory

	return 0;
}

#include<iostream>

using std::cout;
using std::endl;

int main()
{
    // The "capacity" is the maximum number of elements that can be in use at one time.
    // The "size" is the number of elements that are currently in use.
    // These values are in elements, not bytes.  This terminology (size vs. capacity) 
    // comes from the C++ standard library.
    
    // For example, if the size was 10, the first 10 elements of the array
    // should be "in use".
    
    // The size must never be greater than the capacity, because it 
    // makes no sense to e.g., use 101 elements of an 100-element array.
    int capacity{100}; 
    int size{};        

    // create an array of 100 ints.
    // The variable v points to the first element in this array.
    // Note that this array contains exactly 100 ints, numbered 0 through 99
    int* v = new int [capacity];

    // int array_element_size_in_bytes = sizeof(v[0]); // or: sizeof(int)
    // int array_size_in_bytes = capacity * array_element_size_in_bytes;    

	// array elements start at 0.  Every time the next element should be marked as "in use", 
	// increase the count of "elements in use" by one.
	v[size] =  7;  ++size;  // or: v[size++] = 7;
	v[size] = -3;  ++size;
	v[size] =  1;  ++size;
    cout << "Values stored in the array:" << endl;

	for (int i = 0; i < size; ++i)
	{
	  cout << v[i] << "\n";
	}

	delete[] v;
}

#include<iostream>
#include <vector> // https://en.cppreference.com/w/cpp/container/vector

int main( )
{
   std::vector<int> v;

   v.push_back(7);
   v.push_back(-3);
   v.push_back(1);

   std::cout << "The size of the vector is: " << v.size( ) << '\n';

   std::cout << "Values stored in the array:\n";

   for ( unsigned i = 0; i < v.size( ); i++ )
   {
      std::cout << v[ i ] << '\t';
   }
   std::cout << "\n\n";

   std::cout << "Let's try that again\nValues stored in the array:\n:";

   // range-based for loop makes it easier to access every element
   // https://en.cppreference.com/w/cpp/language/range-for
   for ( const auto& i : v )
   {
      std::cout << i << '\t';
   }
   std::cout << '\n';
}

#include<iostream>
#include <vector> // https://en.cppreference.com/w/cpp/container/vector

int main( )
{
   std::vector<int> v;

   v.push_back(7);
   v.push_back(-3);
   v.push_back(1);

   std::cout << "The size of the vector is: " << v.size( ) << '\n';

   std::cout << "Values stored in the array:\n";

   // using a vector's begin/end iterators
   // cbegin/cend so the elements can't be altered)
   for ( auto i = v.cbegin( ); i != v.cend( ); ++i )
   {
      std::cout << *i << '\t';
   }
   std::cout << '\n';
}

#include <iostream>

using std::cout;

using E = int;		// Type of array elements

int main() {
	constexpr size_t N { 100 };					// Number of elements in the array (accessed 0 to N - 1)
	constexpr size_t elementSizeBytes { sizeof(E) };		// Size of an individual element in bytes
	constexpr size_t arraySizeBytes { N * elementSizeBytes };	// Total size of the array in bytes
	const auto v { new E[N]{} };					// Allocate array of size N elements
	size_t counter { };						// Number of non-zero elements in the array

	v[1] = 7; v[2] = -3; v[3] = 1;					// Initialize and store value in elements of array

	cout << "The array has " << N << " elements\n";
	cout << "Each element uses " << elementSizeBytes << " bytes\n";
	cout << "The total size of the array is " << arraySizeBytes << " bytes\n\n";
	cout << "Non-zero values stored in the array are:\n";

	for (size_t i {}; i < N; ++i)
		if (v[i]) {
			++counter;
			cout << v[i] << '\n';		// Print value of each element in the array
		}

	cout << "\nThere are " << counter << " non-zero elements\n";

	delete[] v;							// Free up memory
}

#include <iostream>
#include <memory>

using std::cout;

using E = int;

int main() {
	constexpr size_t N { 100 };
	const auto v { std::make_unique<E[]>(N)};
	size_t counter { };

	v[1] = 7; v[2] = -3; v[3] = 1;

	cout << "The array has " << N << " elements\n";
	cout << "Non-zero values stored in the array are:\n";

	for (size_t i {}; i < N; ++i)
		if (v[i]) {
			++counter;
			cout << v[i] << '\n';		// Print value of each element in the array
		}

	cout << "\nThere are " << counter << " non-zero elements\n";
}