ccan/junkcode/tterribe@email.unc.edu-nmbrthry/gcd.c

#include "gcd.h"

/*Computes the gcd of two integers, _a and _b.
  _a: The first integer of which to compute the gcd.
  _b: The second integer of which to compute the gcd.
  Return: The non-negative gcd of _a and _b.
          If _a and _b are both 0, then 0 is returned, though in reality the
           gcd is undefined, as any integer, no matter how large, will divide 0
           evenly.*/
int gcd(int _a,int _b){
  /*Make both arguments non-negative.
    This forces the return value to be non-negative.*/
  if(_a<0)_a=-_a;
  if(_b<0)_b=-_b;
  /*Simply use the Euclidean algorithm.*/
  while(_b){
    int r;
    r=_a%_b;
    _a=_b;
    _b=r;
  }
  return _a;
}