gcd.h

#ifndef UTIL_GCD_H
#define UTIL_GCD_H
 
/*
* Util Package - C++ Utilities for Scientific Computation
*
* Copyright 2010 - 2017, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
#include <stdlib.h>
 
namespace Util
{
 
   inline int gcd(int a, int b)
   {
      a = abs(a);
      b = abs(b);
      if (a == 0) return b;
      if (b == 0) return a;
      int c;
      // If b > a, swap such that b < a
      if (b > a) {
         c = a;
         a = b;
         b = c;
      }
      // Euclid's algorithm, for a > b > 0
      while (b !=0) {
         c = a % b;
         a = b;
         b = c;
      }
      return a;
   }
 
}
#endif