src/alfred/math/utils.hpp

• View this file on GitHub
• Last update: 2025-03-29 12:01:17+08:00
• Include: #include "src/alfred/math/utils.hpp"

Required by

• src/alfred/math/speed-of-light-power.hpp

Code

#ifndef AFMT_UTIL
#define AFMT_UTIL

// O(sqrt(x)) to judge if x is a prime.
// It will be re-written in Miller-rabin sometime.
constexpr bool is_prime(long long x) {
    if (x < 2) return false;
    for (long long i = 2; i * i <= x; i++) {
        if (x % i == 0) return false;
    }
    return true;
}

template <class T>
inline T gcd(T a, T b) {
    return b == 0 ? a : gcd(b, a % b);
}

template <class T>
inline T lcm(T a, T b) {
    return a / gcd(a, b) * b;
}

#endif // AFMT_UTIL

#line 1 "src/alfred/math/utils.hpp"



// O(sqrt(x)) to judge if x is a prime.
// It will be re-written in Miller-rabin sometime.
constexpr bool is_prime(long long x) {
    if (x < 2) return false;
    for (long long i = 2; i * i <= x; i++) {
        if (x % i == 0) return false;
    }
    return true;
}

template <class T>
inline T gcd(T a, T b) {
    return b == 0 ? a : gcd(b, a % b);
}

template <class T>
inline T lcm(T a, T b) {
    return a / gcd(a, b) * b;
}

Back to top page