cgal/Modular_arithmetic/include/CGAL/Chinese_remainder_traits.h

126 lines
3.4 KiB
C++

// Author(s) : Michael Hemmer <mhemmer@uni-mainz.de>
#ifndef CGAL_CHINESE_REMAINDER_TRAITS_H
#define CGAL_CHINESE_REMAINDER_TRAITS_H 1
#include <CGAL/basic.h>
#include <CGAL/chinese_remainder.h>
#include <CGAL/Algebraic_structure_traits.h>
#include <CGAL/Sqrt_extension.h>
#include <CGAL/Polynomial.h>
#include <vector>
namespace CGAL{
//TODO: 'm' is recomputed again and again in the current scheme.
template <class T> class Chinese_remainder_traits;
template <class T, class TAG> class Chinese_remainder_traits_base;
template <class T> class Chinese_remainder_traits
:public Chinese_remainder_traits_base<T,
typename Algebraic_structure_traits<T>::Algebraic_category>{};
template <class T_>
struct Chinese_remainder_traits_base<T_,Euclidean_ring_tag>{
typedef T_ T;
typedef T_ Scalar_type;
struct Chinese_remainder{
void operator() (
Scalar_type m1, T u1,
Scalar_type m2, T u2,
Scalar_type& m, T& u){
CGAL::chinese_remainder(m1,u1,m2,u2,m,u);
}
};
};
template <class T_, class TAG>
class Chinese_remainder_traits_base{
typedef T_ T;
typedef void Scalar_type;
typedef Null_functor Chinese_remainder;
};
// Spec for Sqrt_extension
// TODO mv to Sqrt_extension.h
template <class NT, class ROOT> class Sqrt_extension;
template <class NT, class ROOT>
struct Chinese_remainder_traits<Sqrt_extension<NT,ROOT> >{
typedef Sqrt_extension<NT,ROOT> T;
typedef Chinese_remainder_traits<NT> CRT_NT;
typedef Chinese_remainder_traits<ROOT> CRT_ROOT;
// SAME AS CRT_ROOT::Scalar_type
typedef typename CRT_NT::Scalar_type Scalar_type;
struct Chinese_remainder{
void operator() (
Scalar_type m1, T u1,
Scalar_type m2, T u2,
Scalar_type& m, T& u){
NT a0,a1;
ROOT root;
typename CRT_NT::Chinese_remainder chinese_remainder_nt;
chinese_remainder_nt(m1,u1.a0(),m2,u2.a0(),m,a0);
if(u1.is_extended() || u2.is_extended()){
chinese_remainder_nt(m1,u1.a1(),m2,u2.a1(),m,a1);
typename CRT_ROOT::Chinese_remainder chinese_remainder_root;
chinese_remainder_root(m1,u1.root(),m2,u2.root(),m,root);
u=T(a0,a1,root);
}else{
u=T(a0);
}
}
};
};
// Spec for Polynomial
// TODO mv to Polynomial.h
template <class NT> class Polynomial;
template <class NT>
struct Chinese_remainder_traits<Polynomial<NT> >{
typedef Polynomial<NT> T;
typedef Chinese_remainder_traits<NT> CRT_NT;
typedef typename CRT_NT::Scalar_type Scalar_type;
struct Chinese_remainder{
void operator() (
Scalar_type m1, T u1,
Scalar_type m2, T u2,
Scalar_type& m, T& u){
typename CRT_NT::Chinese_remainder chinese_remainder_nt;
CGAL_precondition(u1.degree() == u2.degree());
std::vector<NT> coeffs;
coeffs.reserve(u1.degree()+1);
for(int i = 0; i <= u1.degree(); i++){
NT c;
chinese_remainder_nt(m1,u1[i],m2,u2[i],m,c);
coeffs.push_back(c);
}
u = Polynomial<NT>(coeffs.begin(),coeffs.end());
}
};
};
} // namespace CGAL
#endif // CGAL_CHINESE_REMAINDER_TRAITS_H //