Math class

#include "Math.h"

Math::Math()
{
}

Math::~Math()
{
}

double Math::pi = std::acos(-1);

int Math::sign(long n){
    return (n < 0) ? -1 : 1;
}
double Math::round(double n, int r){
    double p = pow(10, r);
    return std::round(n*p) / p;
}
double Math::max(vector<double> t){
    double largest = t[0];
    for (int i = 1; i<t.size(); i++)
    {
        double val = t[i];
        largest = (largest>val) ? largest : val;
    }
    return largest;
}
double Math::min(vector<double> t){
    double lowest = t[0];
    for (int i = 1; i<t.size(); i++)
    {
        double val = t[i];
        lowest = (lowest<val) ? lowest : val;
    }
    return lowest;
}
double Math::gcd(int a, int b){
    while (b != 0){
        int r = a%b;
        a = b;
        b = r;
    }
    return a;
}
double Math::lcm(int a, int b){
    return a*b / gcd(a, b);
}

int Math::modpow(int a, int b, int c){
    if (b == 0)
        return 1 % c;
    if (b == a)
        return a % c;
    int r = modpow(a, b / 2, c);
    return r*r*((b % 2 == 1) ? a : 1) % c;
}
int Math::rand(int min, int max){
    mt19937 rng;
    rng.seed(random_device()());
    uniform_int_distribution<mt19937::result_type> dist1(min, max);
    double ra = std::rand();
    return dist1(rng);
}
long Math::factorial(int n){
    long p = 1;
    for (int i = 2; i <= n; i++){
        p *= i;
    }
    return p;
}