static void apply(const EncryptedArrayDerived<type>& ea,
std::vector<zzX>& unpackSlotEncoding)
{
FHE_NTIMER_START(buildUnpackSlotEncoding);
RBak bak; bak.save(); ea.restoreContext(); // the NTL context for mod p^r
long nslots = ea.size(); // how many slots
long d = ea.getDegree(); // size of each slot
const Mat<R>& CBi=ea.getNormalBasisMatrixInverse();
// CBi contains a description of the normal-basis inverse transformation
std::vector<RX> LM(d);
for (long i = 0; i < d; i++) // prepare the linear polynomial
LM[i] = CBi[i][0];
std::vector<RX> C;
ea.buildLinPolyCoeffs(C, LM); // "build" the linear polynomial
unpackSlotEncoding.resize(d); // encode the coefficients
for (long j = 0; j < d; j++) {
std::vector<RX> v(nslots, C[j]);
ea.encode(unpackSlotEncoding[j], v);
}
}
