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misc_ip.h
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/*****************************************************************************\
* Computer Algebra System SINGULAR
\*****************************************************************************/
/** @file misc_ip.h
*
* This file provides miscellaneous functionality.
*
* ABSTRACT: This file provides the following miscellaneous functionality:
* - prime factorisation of bigints with prime factors < 2^31
* (This will require at most 256 MByte of RAM.)
* - approximate square root of a bigint
*
* Most of the functioanlity implemented here had earlier been
* coded in SINGULAR in some library. Due to performance reasons
* these algorithms have been moved to the C/C++ kernel.
*
* @author Frank Seelisch
*
*
**/
/*****************************************************************************/
#ifndef MISC_H
#define MISC_H
#include "kernel/mod2.h"
#include "coeffs/si_gmp.h"
#include "coeffs/coeffs.h"
#include "Singular/lists.h"
/**
* Factorises a given bigint number n into its prime factors less
* than or equal to a given bound, with corresponding multiplicities.
*
* The method finds all prime factors with multiplicities. If a positive
* bound is given, then only the prime factors <= pBound are being found.
* In this case, there may remain an unfactored portion m of n.
* Also, when n is negative, m will contain the sign. If n is zero, m will
* be zero.
* The method returns a list L filled with three entries:
* L[1] a list; L[1][i] contains the i-th prime factor of |n| as int or
* bigint (sorted in ascending order),
* L[2] a list; L[2][i] contains the multiplicity of L[1, i] in |n| as int
* L[3] contains the remainder m as int or bigint, depending on the size,
*
* We thus have: n = L[1][1]^L[2][1] * ... * L[1][k]^L[2][k] * L[3], where
* k is the number of mutually distinct prime factors (<= a provided non-
* zero bound).
* Note that for n = 0, L[1] and L[2] will be empty lists and L[3] will be
* zero.
*
* @return the factorisation data in a SINGULAR-internal list
**/
lists primeFactorisation(
const number n, /**< [in] the bigint > 0 to be factorised */
const int pBound /**< [in] bound on the prime factors
seeked */
);
#ifdef PDEBUG
#if (OM_TRACK > 2) && defined(OM_TRACK_CUSTOM)
// #include "kernel/polys.h"
/* Needed for debug Version of p_SetRingOfLeftv, Oliver */
#include "kernel/structs.h"
void p_SetRingOfLeftv(leftv l, ring r);
#endif
#endif
#endif
/* MISC_H */
l
int l
Definition cfEzgcd.cc:100
coeffs.h
Coefficient rings, fields and other domains suitable for Singular polynomials.
lists.h
primeFactorisation
lists primeFactorisation(const number n, const int pBound)
Factorises a given bigint number n into its prime factors less than or equal to a given bound,...
Definition misc_ip.cc:358
mod2.h
lists
slists * lists
Definition mpr_numeric.h:146
si_gmp.h
structs.h
leftv
sleftv * leftv
Definition structs.h:53