Math header

#pragma once

#include <vector>
#include <cmath>
#include <random>

using namespace std;

class Math
{
    static double pi;

public:
    Math();
    ~Math();

    static int sign(long);
    static double round(double, int);
    static double max(vector<double>);
    static double min(vector<double>);
    static double gcd(int, int);
    static double lcm(int, int);
    static double PI(){ return pi; }
    static int modpow(int, int, int);
    static int rand(int, int);
    static long factorial(int);
};