/** @file list2703.cpp */
/** Listing 27-3. Adding the reduce Member Function */
#include <cassert>
#include <cstdlib>
#include <iostream>
#include <ostream>

/// Compute the greatest common divisor of two integers, using Euclid’s algorithm.
int gcd(int n, int m)
{
  n = abs(n);
  while (m != 0) {
    int tmp(n % m);
    n = m;
    m = tmp;
  }
  return n;
}

/// Represent a rational number.
struct rational
{
  /// Reduce the numerator and denominator by their GCD.
  void reduce()
  {
    assert(denominator != 0);
    int div(gcd(numerator, denominator));
    numerator = numerator / div;
    denominator = denominator / div;
  }

  int numerator;     ///< numerator gets the sign of the rational value
  int denominator;   ///< denominator is always positive
};

int main()
{
  rational pi;
  pi.numerator = 1420;
  pi.denominator = 452;
  pi.reduce();
  std::cout << "pi is about " << pi.numerator << "/" << pi.denominator << '\n';
}