utility.h

来自「Socketlib: 一个轻量级的C++ 封装Socket C API 网络编程」· C头文件 代码 · 共 40 行

// Greatest common divisor and least common multiple
#pragma once
namespace Util
{

//
// gcd is an algorithm that calculates the greatest common divisor of two
//  integers, using Euclid's algorithm.
//
// Pre: A > 0 && B > 0
// Recommended: A > B
template <typename Integer> 
inline Integer gcd(Integer A, Integer B)
{
  do
  {
    const Integer tmp(B);
    B = A % B;
    A = tmp;
  } while (B != 0);

  return A;
};

//
// lcm is an algorithm that calculates the least common multiple of two
//  integers.
//
// Pre: A > 0 && B > 0
// Recommended: A > B
template <typename Integer> 
inline Integer lcm(const Integer & A, const Integer & B)
{
  Integer ret = A;
  ret /= gcd(A, B);
  ret *= B;
  return ret;
};

};