int count_significance_digit(Float a) {
for (int i = 0; i < 30; i++) {
if (roundto(a, i) == a) {
return i;
}
}
return -1;
}
void EnumerationDyn<FT>::prepare_enumeration(const vector<enumxt> &subtree, bool solvingsvp,
bool subtree_reset)
{
is_svp = solvingsvp;
enumf newdist = 0.0;
k_end = d - subtree.size();
for (k = d - 1; k >= 0 && newdist <= maxdist; --k)
{
enumf newcenter = center_partsum[k];
if (k >= k_end)
{
// use subtree
x[k] = subtree[k - k_end];
if (x[k] != 0)
is_svp = false;
for (int j = 0; j < k; ++j)
center_partsum[j] -= x[k] * mut[j][k];
}
else
{
if (dual)
{
for (int j = k + 1; j < k_end; ++j)
newcenter -= alpha[j] * mut[k][j];
}
else
{
for (int j = k + 1; j < k_end; ++j)
newcenter -= x[j] * mut[k][j];
}
roundto(x[k], newcenter); // newX = rint(newCenter) / lrint(newCenter)
center[k] = newcenter;
partdist[k] = newdist;
dx[k] = ddx[k] = (((int)(newcenter >= x[k]) & 1) << 1) - 1;
}
if (!subtree_reset || k < k_end)
{
alpha[k] = x[k] - newcenter;
newdist += alpha[k] * alpha[k] * rdiag[k];
}
}
if (!is_svp)
{
k_max = k_end; // The last non-zero coordinate of x will not stay positive
}
else
{
k_max = 0;
x[0] = 1; // Excludes (0,...,0) from the enumeration
}
++k;
}
inline void EnumerationBase::enumerate_recursive(
EnumerationBase::opts<kk, kk_start, dualenum, findsubsols, enable_reset>)
{
enumf alphak = x[kk] - center[kk];
enumf newdist = partdist[kk] + alphak * alphak * rdiag[kk];
if (!(newdist <= partdistbounds[kk]))
return;
++nodes;
alpha[kk] = alphak;
if (findsubsols && newdist < subsoldists[kk])
{
subsoldists[kk] = newdist;
process_subsolution(kk, newdist);
}
if (kk == 0)
{
if (newdist > 0.0 || !is_svp)
process_solution(newdist);
}
else if (enable_reset &&
kk < reset_depth) // in CVP, below the max GS vector, we reset the partial distance
{
reset(newdist, kk);
return;
}
else
{
partdist[kk - 1] = newdist;
if (dualenum)
{
for (int j = center_partsum_begin[kk]; j > kk - 1; --j)
center_partsums[kk - 1][j] = center_partsums[kk - 1][j + 1] - alpha[j] * mut[kk - 1][j];
}
else
{
for (int j = center_partsum_begin[kk]; j > kk - 1; --j)
center_partsums[kk - 1][j] = center_partsums[kk - 1][j + 1] - x[j] * mut[kk - 1][j];
}
if (center_partsum_begin[kk] > center_partsum_begin[kk - 1])
center_partsum_begin[kk - 1] = center_partsum_begin[kk];
center_partsum_begin[kk] = kk;
center[kk - 1] = center_partsums[kk - 1][kk];
roundto(x[kk - 1], center[kk - 1]);
dx[kk - 1] = ddx[kk - 1] = (((int)(center[kk - 1] >= x[kk - 1]) & 1) << 1) - 1;
}
while (true)
{
FPLLL_TRACE("Level k=" << kk << " dist_k=" << partdist[kk] << " x_k=" << x[kk]
<< " newdist=" << newdist << " partdistbounds_k=" << partdistbounds[kk]);
enumerate_recursive(opts<kk - 1, kk_start, dualenum, findsubsols, enable_reset>());
if (partdist[kk] != 0.0)
{
x[kk] += dx[kk];
ddx[kk] = -ddx[kk];
dx[kk] = ddx[kk] - dx[kk];
enumf alphak2 = x[kk] - center[kk];
enumf newdist2 = partdist[kk] + alphak2 * alphak2 * rdiag[kk];
if (!(newdist2 <= partdistbounds[kk]))
return;
++nodes;
alpha[kk] = alphak2;
if (kk == 0)
{
if (newdist2 > 0.0 || !is_svp)
process_solution(newdist2);
}
else
{
partdist[kk - 1] = newdist2;
if (dualenum)
center_partsums[kk - 1][kk - 1 + 1] =
center_partsums[kk - 1][kk - 1 + 1 + 1] - alpha[kk - 1 + 1] * mut[kk - 1][kk - 1 + 1];
else
center_partsums[kk - 1][kk - 1 + 1] =
center_partsums[kk - 1][kk - 1 + 1 + 1] - x[kk - 1 + 1] * mut[kk - 1][kk - 1 + 1];
if (kk > center_partsum_begin[kk - 1])
center_partsum_begin[kk - 1] = kk;
center[kk - 1] = center_partsums[kk - 1][kk - 1 + 1];
roundto(x[kk - 1], center[kk - 1]);
dx[kk - 1] = ddx[kk - 1] = (((int)(center[kk - 1] >= x[kk - 1]) & 1) << 1) - 1;
}
}
else
{
++x[kk];
enumf alphak2 = x[kk] - center[kk];
enumf newdist2 = partdist[kk] + alphak2 * alphak2 * rdiag[kk];
if (!(newdist2 <= partdistbounds[kk]))
return;
++nodes;
alpha[kk] = alphak2;
if (kk == 0)
{
if (newdist2 > 0.0 || !is_svp)
process_solution(newdist2);
}
else
{
partdist[kk - 1] = newdist2;
if (dualenum)
center_partsums[kk - 1][kk - 1 + 1] =
center_partsums[kk - 1][kk - 1 + 1 + 1] - alpha[kk - 1 + 1] * mut[kk - 1][kk - 1 + 1];
else
center_partsums[kk - 1][kk - 1 + 1] =
center_partsums[kk - 1][kk - 1 + 1 + 1] - x[kk - 1 + 1] * mut[kk - 1][kk - 1 + 1];
if (kk > center_partsum_begin[kk - 1])
center_partsum_begin[kk - 1] = kk;
center[kk - 1] = center_partsums[kk - 1][kk - 1 + 1];
roundto(x[kk - 1], center[kk - 1]);
dx[kk - 1] = ddx[kk - 1] = (((int)(center[kk - 1] >= x[kk - 1]) & 1) << 1) - 1;
}
}
}
}
template <bool dualenum, bool findsubsols, bool enable_reset> void EnumerationBase::enumerate_loop()
{
if (k >= k_end)
return;
for (int i = 0; i < k_end; ++i)
{
center_partsum_begin[i + 1] = k_end - 1;
center_partsums[i][k_end] = center_partsum[i];
}
partdist[k_end] = 0.0; // needed to make next_pos_up() work properly
nodes -= k_end - k;
k = k_end - 1;
#ifdef FPLLL_WITH_RECURSIVE_ENUM
enumerate_recursive_dispatch<dualenum, findsubsols, enable_reset>(k);
return;
#endif
finished = false;
while (!finished)
{
enumf alphak = x[k] - center[k];
enumf newdist = partdist[k] + alphak * alphak * rdiag[k];
FPLLL_TRACE("Level k=" << k << " dist_k=" << partdist[k] << " x_k=" << x[k]
<< " newdist=" << newdist << " partdistbounds_k=" << partdistbounds[k]);
if (newdist <= partdistbounds[k])
{
++nodes;
alpha[k] = alphak;
if (findsubsols && newdist < subsoldists[k])
{
subsoldists[k] = newdist;
process_subsolution(k, newdist);
}
--k;
if (k < 0)
{
if (newdist > 0.0 || !is_svp)
process_solution(newdist);
finished = !next_pos_up();
continue;
}
if (enable_reset &&
k < reset_depth) // in CVP, below the max GS vector, we reset the partial distance
{
reset(newdist, k);
finished = !next_pos_up();
continue;
}
if (dualenum)
{
for (int j = center_partsum_begin[k + 1]; j > k; --j)
center_partsums[k][j] = center_partsums[k][j + 1] - alpha[j] * mut[k][j];
}
else
{
for (int j = center_partsum_begin[k + 1]; j > k; --j)
center_partsums[k][j] = center_partsums[k][j + 1] - x[j] * mut[k][j];
}
center_partsum_begin[k] = max(center_partsum_begin[k], center_partsum_begin[k + 1]);
center_partsum_begin[k + 1] = k + 1;
enumf newcenter = center_partsums[k][k + 1];
center[k] = newcenter;
partdist[k] = newdist;
roundto(x[k], newcenter);
dx[k] = ddx[k] = (((int)(newcenter >= x[k]) & 1) << 1) - 1;
}
else
{
finished = !next_pos_up();
}
}
}
