powerest.hpp

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/*****************************************************************************
    
    powerest.hpp -- Íàáîð ïîëåçíûõ ìàòåìàòè÷åñêèõ óòèëèò.

    Ýòîò ôàéë ÿâëÿåòñÿ ÷àñòüþ áèáëèîòåêè Arageli.

    Copyright (C) Nikolai Yu. Zolotykh, 1999--2006
    Copyright (C) Sergey S. Lyalin, 2005
    University of Nizhni Novgorod, Russia

*****************************************************************************/

#ifndef _ARAGELI_powerest_hpp_
#define _ARAGELI_powerest_hpp_

#include "config.hpp"
#include "exception.hpp"
#include "factory.hpp"
#include "cmp.hpp"

#include "std_import.hpp"


namespace Arageli
{



template <typename T, typename I, typename T_factory>
T power (T a, I n, const T_factory& tfctr);

template <typename T, typename I>
inline T power (const T& a, const I& n)
{ return power(a, n, factory<T>()); }


template <typename T, typename I, typename T_factory>
inline T pow2 (I n, const T_factory& tfctr)
{
    T res = tfctr.unit();
    return res <<= n;
}

template <typename T, typename I>
inline T pow2 (I n)
{
    T res = unit<T>();
    return res <<= n;
}


template <typename T>
inline T log2 (T x)
{ return log(x)/log(2.0l); }



template <typename T1, typename T2, typename Q, typename R>
inline void divide (const T1& a, const T2& b, Q& q, R& r)
{
    q = a/b;
    r = a%b;
    ARAGELI_ASSERT_1(a == b*q + r);
}


//  @param b divisor
//  @param q the resulting quotient
//  @param r the resulting remainder    */
//template <typename T1, typename T2, typename Q, typename R>
//inline void divide (const T1& a, const T2& b, Q& q, R& r)
//{
//  divide
//  (
//      a, b, q, r,
//      type_traits<T1>(), type_traits<T2>(),
//      type_traits<Q>(), type_traits<R>()
//  );
//}
//
//

template <typename T1, typename T2, typename Q, typename R>
inline void prdivide (const T1& a, const T2& b, Q& q, R& r)
{
    divide(a, b, q, r);
    
    if(is_negative(r))
    {
        if(is_positive(b)){ --q; r += b; }
        else { ++q; r -= b; }
    }
    
    ARAGELI_ASSERT_1(a == b*q + r);
    ARAGELI_ASSERT_1(sign(r) >= 0);
    ARAGELI_ASSERT_1(is_positive(b) ? r < b : r < -b);
}


//  @param b divisor
//  @param q the resulting quotient
//  @param r the resulting remainder, 0 <= r < |b|  */
//template <typename T1, typename T2, typename Q, typename R>
//inline void prdivide (const T1& a, const T2& b, Q& q, R& r)
//{
//  prdivide
//  (
//      a, b, q, r,
//      type_traits<T1>(), type_traits<T2>(),
//      type_traits<Q>(), type_traits<R>()
//  );
//}


template <typename T1, typename T2>
inline T1 prquot (const T1& a, const T2& b)
{
    T1 q; T2 r;
    prdivide(a, b, q, r);
    return q;
}

//template <typename T1, typename T2>
//inline T1 prquot (const T1& a, const T2& b)
//{ return prquot(a, b, type_traits<T1>(), type_traits<T2>()); }


template <typename T1, typename T2>
inline T2 prrem (const T1& a, const T2& b)
{
    T1 q; T2 r;
    prdivide(a, b, q, r);
    return r;
}

//template <typename T1, typename T2>
//inline T2 prrem (const T1& a, const T2& b)
//{ return prrem(a, b, type_traits<T1>(), type_traits<T2>()); }


template <typename T>
inline T square (const T& a)
{ return a*a; }


inline int pow (int x, int y)
{ return power(x, y); }


//template <typename T>
//inline T square (const T& a)
//{ return square(a, type_traits<T>()); }


} // namespace Arageli


#ifdef ARAGELI_INCLUDE_CPP_WITH_EXPORT_TEMPLATE
    #define ARAGELI_INCLUDE_CPP_WITH_EXPORT_TEMPLATE_POWEREST
    #include "powerest.cpp"
    #undef  ARAGELI_INCLUDE_CPP_WITH_EXPORT_TEMPLATE_POWEREST
#endif


#endif  //  #ifndef _ARAGELI_powerest_hpp_

---