17 #ifndef HPP_CORE_PATH_MATH_HH
18 #define HPP_CORE_PATH_MATH_HH
31 for (
size_type i = 1; i < N; ++i) ret(i) = ret(i-1) * i;
39 assert (n >= k && k >= 0);
41 size_type denom = factors(k) * factors(n - k);
42 return factors (n) / denom;
49 #endif // HPP_CORE_PATH_MATH_HH