// Implementation of scrt += poly, scrt -= poly, or scrt *= poly. This
// implementation is safe for "in place" operation, e.g., s += s.map[i]
SingleCRT& SingleCRT::Op(const ZZX &poly,
void (*Fnc)(ZZ&, const ZZ&, const ZZ&, const ZZ&))
{
const IndexSet& s = map.getIndexSet();
ZZX poly1, poly2;
poly1 = poly;
for (long i = s.first(); i <= s.last(); i = s.next(i)) {
ZZ pi = to_ZZ(context.ithPrime(i));
poly2 = poly1;
PolyRed(poly2,pi,/*abs=*/true); // abs=true means reduce to [0,pi-1)
vec_ZZ& vp1 = map[i].rep;
vec_ZZ& vp2 = poly2.rep;
long len1 = vp1.length();
long len2 = vp2.length();
long maxlen = max(len1, len2);
vp1.SetLength(maxlen);
for (long j=len1; j < maxlen; j++) clear(vp1[j]);
for (long j=0; j<len2; j++)
Fnc(vp1[j], vp1[j], vp2[j], pi);
map[i].normalize();
}
return *this;
}
// Here Fnc is either Add(ZZX,ZZX,ZZ), Sub(ZZX,ZZX,ZZ), or Mul(ZZX,ZZX,ZZ)
// FIXME: this is not alias friendly
SingleCRT& SingleCRT::Op(const ZZ &num, void (*Fnc)(ZZX&, const ZZX&, const ZZ&))
{
const IndexSet& s = map.getIndexSet();
ZZ pi;
ZZ n;
ZZX poly1;
for (long i = s.first(); i <= s.last(); i = s.next(i)) {
conv(pi, context.ithPrime(i));
rem(n, num, pi); // n = num % pi
poly1 = map[i];
Fnc(poly1,poly1,n);
PolyRed(poly1,pi,/*abs=*/true); // abs=true means reduce to [0,pi-1)
map[i] = poly1;
}
return *this;
}
// Generic operators, Fnc is either AddMod or SubMod
// This should have been a template, but gcc refuses to cooperate
SingleCRT& SingleCRT::Op(const SingleCRT &other,
void (*Fnc)(ZZ&, const ZZ&, const ZZ&, const ZZ&),
bool matchIndexSets)
{
if (&context != &other.context)
Error("SingleCRT::Op: incomopatible objects");
// Match the index sets, if needed
if (matchIndexSets && !(map.getIndexSet() >= other.map.getIndexSet()))
addPrimes(other.map.getIndexSet() / map.getIndexSet()); // This is expensive
// INVARIANT: map.getIndexSet() >= other.map.getIndexSet())
SingleCRT tmp(context); // a rare case where you want an empty SingleCRT object
const IndexMap<ZZX>* other_map = &other.map;
if (map.getIndexSet() > other.map.getIndexSet()) { // Even more expensive
tmp = other;
tmp.addPrimes(map.getIndexSet() / other.map.getIndexSet());
other_map = &tmp.map;
}
const IndexSet& s = map.getIndexSet();
// add/sub polynomial, modulo the respective primes
for (long i = s.first(); i <= s.last(); i = s.next(i)) {
ZZ pi = to_ZZ(context.ithPrime(i));
vec_ZZ& vp1 = map[i].rep;
const vec_ZZ& vp2 = (*other_map)[i].rep;
long len1 = vp1.length();
long len2 = vp2.length();
long maxlen = max(len1, len2);
vp1.SetLength(maxlen);
for (long j=len1; j < maxlen; j++) clear(vp1[j]);
for (long j=0; j<len2; j++)
Fnc(vp1[j], vp1[j], vp2[j], pi);
map[i].normalize();
}
return *this;
}
int main()
{
Prn(Fnc(20.2,3));
}
inline return_type operator()(const class_type& obj) const
{
return obj.*member_variable.*Fnc();
}
