gcd.hpp

浮点数基本运算 浮点数的基本运算主要有四则运算、符号处理、大小比较

// GCD implementation -*- C++ -*-

// Copyright (C) 2005 Ben T. Bear
//
// This file is part of the BTB's Template<Integer> Library.  This
// library is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this library; see the file COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
// MA 02111-1307, USA.

// As a special exception, you may use this file as part of a free
// software library without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to
// produce an executable, this file does not by itself cause the
// resulting executable to be covered by the GNU General Public
// License.  This exception does not however invalidate any other
// reasons why the executable file might be covered by the GNU General
// Public License.

#ifndef __bt2il_gcd_lcm_hpp
#define __bt2il_gcd_lcm_hpp

namespace btil
{
  template <int m, int n>
  struct gcd;

  template <int m, int n>
  struct lcm;

  
  template <int m, int n, int r>
  struct __gcd;

  template <int m, int n>
  struct __gcd<m, n, 0>
  {
    static const int value = n;
  };
  
  template <int m, int n, int r>
  struct __gcd
  {
    static const int value = __gcd<n, r, n%r>::value;
  };

  template <int m, int n>
  struct gcd
  {
    static const int __m = (m > n) ? m : n;
    static const int __n = (m > n) ? n : m; // m + n - __m;

    static const int value = __gcd<__m, __n, __m % __n>::value;
  };

  
  template <int m, int n>
  struct lcm
  {
    static const int value = m * n / gcd<m, n>::value;
  };
}

#endif