#include <iostream>
#include <cmath>

// compiled with "g++ -std=c++11 -fsanitize=undefined -g fractional_test.cpp" using gcc 5.4 for x86_64 on linux

// start copied from CglGomory.cpp
typedef struct {
  int numerator;
  int denominator;
} Rational;
inline Rational nearestRational(double value, int maxDenominator) 
{
  Rational tryThis;
  Rational tryA;
  Rational tryB;
  double integerPart;

#if CGL_DEBUG>1
  printf("Rational of %g is ",value);
#endif
  int nLoop=0;

  tryA.numerator=0;
  tryA.denominator=1;
  tryB.numerator=1;
  tryB.denominator=0;

  if (fabs(value)<1.0e-10)
    return tryA;
  integerPart = floor(value);
  value -= integerPart;
  tryThis.numerator = tryB.numerator* static_cast<int> (integerPart) + tryA.numerator;
  tryThis.denominator = tryB.denominator* static_cast<int> (integerPart) + tryA.denominator;
  tryA = tryB;
  tryB = tryThis;

  while (value>1.0e-10 && tryB.denominator <=maxDenominator) {
    nLoop++;
    if (nLoop>50) {
      Rational bad;
      bad.numerator=-1;
      bad.denominator=-1;
#if CGL_DEBUG>1
      printf(" *** bad rational\n");
#endif
      return bad;
    }
    value = 1.0/value;
    integerPart = floor(value+1.0e-10);
    value -= integerPart;
    tryThis.numerator = tryB.numerator* static_cast<int> (integerPart) + tryA.numerator;
    tryThis.denominator = tryB.denominator* static_cast<int>(integerPart) + tryA.denominator;
    tryA = tryB;
    tryB = tryThis;
  }
  if (tryB.denominator <= maxDenominator) {
#if CGL_DEBUG>1
    printf("%d/%d\n",tryB.numerator,tryB.denominator);
#endif
    return tryB;
  } else {
#if CGL_DEBUG>1
    printf("%d/%d\n",tryA.numerator,tryA.denominator);
#endif
    return tryA;
  }
}
// end copied from CglGomory.cpp

void test(double numerator) {
	auto frac = nearestRational(numerator, 100000);
	double result = static_cast<double>(frac.numerator) / frac.denominator;
	std::cout << frac.numerator << " / " << frac.denominator << " = " << result << std::endl;
}

int main() {
	test(0.5407407407407234);
	test(0.8111111111111367);
}