Dynamic memory allocation in C++

To run a C++ program:

• Edit a file with any plain-text editor (gedit, emacs, pico/nano, or other), save it with the extension .cpp (for this example assume myprogram.cpp)
• Open a terminal window, use cd command to get to the folder where your C++ files are
• Type g++ myprogram.cpp to compile. If there are error messages, correct the mistake and compile again (note: an old executable a.out will still be there until it is overwritten by a new one. If your program failed to compile and you still try to run it, you would be running the old version).
• After a successful compilation you can run your program by typing a.out on the command line. If you get file not found error, use ./a.out instead.

The example of using dynamic memory allocation

#include 
#include  // need this to use malloc
using namespace std;

int main () {
  int n, i;
  int * numbers;

  cout << "Please enter a number: ";
  cin >> n;

  // allocate memory for n integers:
  numbers = (int *) malloc(n * sizeof(int));

  for (i = 0; i < n; ++i) {
    numbers[i] = i;

  }

  for (i = 0; i < n; ++i) {
    cout << numbers[i] << " ";
  }

  cout << endl;
  // free the memory at the end
  free(numbers);

}