GCD & LCM¶

#include <numeric>

-std=c++17

template< class M, class N >
constexpr std::common_type_t<M, N> gcd( M m, N n );

template< class M, class N >
constexpr std::common_type_t<M, N> lcm( M m, N n );

int gcd(int x, int y) {
    return y>0 ? gcd(y, x%y) : x;
}

int gcd(int x, int y) {
    while (y^=x^=y^=x%=y);
    return x;
}