Function countr_zero_constexpr

atcoder/internal_bit.hpp:45–49

@param n `1 <= n` @return same with std::bit::countr_zero

// @param n `1 <= n`
// @return same with std::bit::countr_zero
constexpr int countr_zero_constexpr(unsigned int n) {
    int x = 0;
    while (!(n & (1 << x))) x++;
    return x;
}

}  // namespace internal