void mpq_mat_init(mpq_mat_t mat, ulong r, ulong c)
{
if ((r) && (c)) mat->entries = (mpq_t*) flint_heap_alloc_bytes(r*c*sizeof(mpq_t));
else mat->entries = NULL;
long i;
for (i = 0; i < r*c; i++)
{
mpq_init(mat->entries[i]);
}
mat->r = r;
mat->c = c;
}
void fmpz_comb_init(fmpz_comb_t comb, ulong * primes, ulong num_primes)
{
ulong i, j, k;
comb->primes = primes;
comb->num_primes = num_primes;
ulong n = 0L;
while (num_primes > (1L<<n)) n++;
comb->n = n;
ulong num;
// create zn_poly modulus information
comb->mod = (zn_mod_t *) flint_heap_alloc_bytes(sizeof(zn_mod_t)*num_primes);
for (ulong i = 0; i < num_primes; i++)
zn_mod_init(comb->mod[i], primes[i]);
if (n == 0) return; // nothing to do
// allocate space for comb
comb->comb = (fmpz_t **) flint_heap_alloc(n);
j = (1L<<(n - 1));
ulong size = 2;
mp_limb_t * ptr;
for (i = 0; i < n; i++)
{
comb->comb[i] = (fmpz_t *) flint_heap_alloc(j);
ptr = (mp_limb_t *) flint_heap_alloc((1L<<n) + j);
for (k = 0; k < j; k++, ptr += (size + 1))
{
comb->comb[i][k] = ptr;
}
j/=2;
size*=2;
}
// allocate space for res
comb->res = (fmpz_t **) flint_heap_alloc(n);
j = (1L<<(n - 1));
size = 2;
for (i = 0; i < n; i++)
{
comb->res[i] = (fmpz_t *) flint_heap_alloc(j);
ptr = (mp_limb_t *) flint_heap_alloc((1L<<n) + j);
for (k = 0; k < j; k++, ptr += (size + 1))
{
comb->res[i][k] = ptr;
}
j/=2;
size*=2;
}
// compute products of pairs of primes and place in comb
for (i = 0, j = 0; i + 2 <= num_primes; i += 2, j++)
{
fmpz_set_ui(comb->comb[0][j], primes[i]);
fmpz_mul_ui(comb->comb[0][j], comb->comb[0][j], primes[i+1]);
}
if (i < num_primes) // in case number of primes is odd
{
fmpz_set_ui(comb->comb[0][j], primes[i]);
i+=2;
j++;
}
num = (1L<<n); // set the rest of the entries on that row of the comb to 1
for (; i < num; i += 2, j++)
{
fmpz_set_ui(comb->comb[0][j], 1L);
}
// compute rest of comb by multiplying in pairs
ulong log_comb = 1;
num /= 2;
while (num >= 2)
{
for (i = 0, j = 0; i < num; i += 2, j++)
{
fmpz_mul(comb->comb[log_comb][j], comb->comb[log_comb-1][i], comb->comb[log_comb-1][i+1]);
}
log_comb++;
num /= 2;
}
// compute inverses from pairs of primes
fmpz_t temp = (fmpz_t) flint_stack_alloc(2);
fmpz_t temp2 = (fmpz_t) flint_stack_alloc(2);
for (i = 0, j = 0; i + 2 <= num_primes; i += 2, j++)
{
fmpz_set_ui(temp, primes[i]);
fmpz_set_ui(temp2, primes[i+1]);
fmpz_invert(comb->res[0][j], temp, temp2);
}
flint_stack_release(); //temp2
flint_stack_release(); //temp
ulong log_res = 1;
num = (1L<<(n - 1));
// compute remaining inverses, each level combining pairs from the level below
while (log_res < n)
{
for (i = 0, j = 0; i < num; i += 2, j++)
{
fmpz_invert(comb->res[log_res][j], comb->comb[log_res-1][i], comb->comb[log_res-1][i+1]);
}
log_res++;
num /= 2;
}
}