Ответ:

#include <iostream>

void addHeight(double& height, int& size, double*& arr)

{

if (arr == nullptr)

{

 arr = new double[4];

 arr[0] = height;

 return;

}

if ((size + 1) % 4 == 0)

{

 double* temp = new double[size + 1 + 4];

 for (int i = 0; i < size; i++)

 {

  temp[i] = arr[i];

 }

 delete[] arr;

 arr = temp;

}

arr[size] = height;

}

int main()

{

double* height = nullptr;

int size = 0;

while (true)

{

 double elem = 0;

 std::cout << "Enter height (END WITH '0'): ";

 std::cin >> elem;

 if (elem < 0)

 {

  std::cout << "Error: height should be more than 0\n";

  continue;

 }

 else if (elem == 0)

 {

  break;

 }

 addHeight(elem, size, height);

 size++;

}

double sum = 0;

for (int i = 0; i < size; i++)

{

 sum += height[i];

}

std::cout.precision(2);

std::cout << std::fixed << "Overall height: " << sum << std::endl;

std::cout << std::fixed << "Average height: " << sum / size << std::endl;

delete[] height;

return 0;

}

Объяснение: