My code

… was written in C++11 and can be compiled with G++, Clang++, Visual C++. You can download it, too. Or just jump to my GitHub repository.

The code contains #ifdefs to switch between the original problem and the Hackerrank version.
Enable #ifdef ORIGINAL to produce the result for the original problem (default setting for most problems).

       
#include <iostream>
       
#include <vector>
       
 
       
//#define ORIGINAL

       
 
       
int main()
       
{
       
#ifdef ORIGINAL
       
  unsigned int limit = 1000000; // "less than one million"
       
#else
       
  unsigned int limit = 8000001; // up to 8 million (inclusive)
       
#endif
       
 
       
  // precompute solutions
       
  std::vector<unsigned int> solutions(limit, 0);
       
  for (unsigned int a = 1; a < limit; a++)
       
    for (auto b = (a + 3) / 4; b < a; b++)
       
    {
       
      auto current = a * (4*b - a);
       
      if (current >= limit)
       
        break;
       
 
       
      solutions[current]++;
       
    }
       
 
       
#ifdef ORIGINAL
       
  // count all with exactly 10 solutions
       
  unsigned int count = 0;
       
  for (auto s : solutions)
       
    if (s == 10)
       
      count++;
       
  std::cout << count << std::endl;
       
 
       
#else
       
 
       
  // look up number of solutions
       
  unsigned int tests;
       
  std::cin >> tests;
       
  while (tests--)
       
  {
       
    unsigned int pos;
       
    std::cin >> pos;
       
    std::cout << solutions[pos] << std::endl;
       
  }
       
#endif
       
 
       
  return 0;
       
}

This solution contains 8 empty lines, 4 comments and 8 preprocessor commands.