My code

… was written in C++11 and can be compiled with G++, Clang++, Visual C++. You can download it, as well as the input data, 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 <cmath>
       
#include <map>
       
#include <iostream>
       
 
       
#define ORIGINAL
       
 
       
int main()
       
{
       
#ifdef ORIGINAL
       
  // read all 1000 pairs, store [logarithm] => [index]
       
  std::map<double, unsigned int> data;
       
  for (unsigned int i = 1; i <= 1000; i++) // first line has index 1 (not 0)
       
  {
       
    unsigned int base, exponent;
       
    char comma; // skip commas in input file
       
    std::cin >> base >> comma >> exponent;
       
 
       
    // sort by exponent * log(base)
       
    data[exponent * log(base)] = i;
       
  }
       
  // return index of last input line
       
  std::cout << data.rbegin()->second << std::endl;
       
 
       
  return 0;
       
 
       
#else
       
 
       
  // how many pairs ?
       
  unsigned int numbers;
       
  std::cin >> numbers;
       
 
       
  // read all pairs, store [logarithm] => [base, exponent]
       
  std::map<double, std::pair<unsigned int, unsigned int>> data;
       
  for (unsigned int i = 1; i <= numbers; i++)
       
  {
       
    unsigned int base, exponent;
       
    std::cin >> base >> exponent;
       
    data[exponent * log(base)] = std::make_pair(base, exponent);
       
  }
       
 
       
  // which number of the sorted list should be printed ?
       
  unsigned int pos;
       
  std::cin >> pos;
       
 
       
  // std::map is sorted, jump to the position
       
  auto i = data.begin();
       
  std::advance(i, pos - 1); // input is 1-based
       
 
       
  // get result
       
  auto result   = i->second;
       
  auto base     = result.first;
       
  auto exponent = result.second;
       
  // and print it
       
  std::cout << base << " " << exponent << std::endl;
       
 
       
  return 0;
       
#endif
       
}

This solution contains 11 empty lines, 9 comments and 7 preprocessor commands.