#if !defined(_gcd_H) # define _gcd_H (1) /*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); #endif