void fmpz_poly_q_scalar_mul_si(fmpz_poly_q_t rop, const fmpz_poly_q_t op, long x)
{
fmpz_t cont, fx, gcd;
if (fmpz_poly_q_is_zero(op) || (x == 0))
{
fmpz_poly_q_zero(rop);
return;
}
if (x == 1)
{
fmpz_poly_q_set(rop, op);
return;
}
fmpz_init(cont);
fmpz_poly_content(cont, op->den);
if (fmpz_is_one(cont))
{
fmpz_poly_scalar_mul_si(rop->num, op->num, x);
fmpz_poly_set(rop->den, op->den);
fmpz_clear(cont);
return;
}
fmpz_init(fx);
fmpz_init(gcd);
fmpz_set_si(fx, x);
fmpz_gcd(gcd, cont, fx);
if (fmpz_is_one(gcd))
{
fmpz_poly_scalar_mul_si(rop->num, op->num, x);
fmpz_poly_set(rop->den, op->den);
}
else
{
fmpz_divexact(fx, fx, gcd);
fmpz_poly_scalar_mul_fmpz(rop->num, op->num, fx);
fmpz_poly_scalar_divexact_fmpz(rop->den, op->den, gcd);
}
fmpz_clear(cont);
fmpz_clear(fx);
fmpz_clear(gcd);
}
/**
* \ingroup StringConversions
*
* Sets the rational function \c rop to the value specified by the
* null-terminated string \c s.
*
* This method has now already been somewhat improved and is not very tolerant
* in the handling of malformed input. It expects either legitimate input for
* an \c fmpz_poly_t element, or two such inputs separated by a <tt>/</tt>
* only, in which case it is also assumed that the second polynomial is
* non-zero.
*
* The rational function is brought into canonical form by calling
* #fmpz_poly_q_canonicalize() in this function.
*
* Returns \c 0 if the string represents a valid rational function and
* \c non-zero otherwise.
*/
int fmpz_poly_q_set_str(fmpz_poly_q_t rop, const char *s)
{
int ans, i, m;
size_t len;
char * numstr;
len = strlen(s);
for (m = 0; m < len; m++)
{
if (s[m] == '/')
break;
}
if (m == len)
{
ans = fmpz_poly_set_str(rop->num, s);
fmpz_poly_set_si(rop->den, 1);
return ans;
}
else
{
numstr = flint_malloc(m + 1);
if (!numstr)
{
flint_printf("Exception (fmpz_poly_q_set_str). Memory allocation failed.\n");
abort();
}
for (i = 0; i < m; i++)
numstr[i] = s[i];
numstr[i] = '\0';
ans = fmpz_poly_set_str(rop->num, numstr);
ans |= fmpz_poly_set_str(rop->den, s + (m + 1));
if (ans == 0)
fmpz_poly_q_canonicalise(rop);
else
fmpz_poly_q_zero(rop);
flint_free(numstr);
return ans;
}
}
void test_zero(char * in, char * out)
{
int ans;
fmpz_poly_q_t op;
char * res;
fmpz_poly_q_init(op);
fmpz_poly_q_set_str(op, in);
fmpz_poly_q_zero(op);
res = fmpz_poly_q_get_str(op);
ans = !strcmp(res, out);
if (!ans)
{
flint_printf("test_zero: failed\n");
flint_printf(" Expected \"%s\", got \"%s\"\n", out, res);
abort();
}
fmpz_poly_q_clear(op);
flint_free(res);
}
void fmpz_poly_q_mul(fmpz_poly_q_t rop,
const fmpz_poly_q_t op1, const fmpz_poly_q_t op2)
{
if (fmpz_poly_q_is_zero(op1) || fmpz_poly_q_is_zero(op2))
{
fmpz_poly_q_zero(rop);
return;
}
if (op1 == op2)
{
fmpz_poly_pow(rop->num, op1->num, 2);
fmpz_poly_pow(rop->den, op1->den, 2);
return;
}
if (rop == op1 || rop == op2)
{
fmpz_poly_q_t t;
fmpz_poly_q_init(t);
fmpz_poly_q_mul(t, op1, op2);
fmpz_poly_q_swap(rop, t);
fmpz_poly_q_clear(t);
return;
}
/*
From here on, we may assume that rop, op1 and op2 refer to distinct
objects in memory, and that op1 and op2 are non-zero
*/
/* Polynomials? */
if (fmpz_poly_length(op1->den) == 1 && fmpz_poly_length(op2->den) == 1)
{
const slong len1 = fmpz_poly_length(op1->num);
const slong len2 = fmpz_poly_length(op2->num);
fmpz_poly_fit_length(rop->num, len1 + len2 - 1);
if (len1 >= len2)
{
_fmpq_poly_mul(rop->num->coeffs, rop->den->coeffs,
op1->num->coeffs, op1->den->coeffs, len1,
op2->num->coeffs, op2->den->coeffs, len2);
}
else
{
_fmpq_poly_mul(rop->num->coeffs, rop->den->coeffs,
op2->num->coeffs, op2->den->coeffs, len2,
op1->num->coeffs, op1->den->coeffs, len1);
}
_fmpz_poly_set_length(rop->num, len1 + len2 - 1);
_fmpz_poly_set_length(rop->den, 1);
return;
}
fmpz_poly_gcd(rop->num, op1->num, op2->den);
if (fmpz_poly_is_one(rop->num))
{
fmpz_poly_gcd(rop->den, op2->num, op1->den);
if (fmpz_poly_is_one(rop->den))
{
fmpz_poly_mul(rop->num, op1->num, op2->num);
fmpz_poly_mul(rop->den, op1->den, op2->den);
}
else
{
fmpz_poly_div(rop->num, op2->num, rop->den);
fmpz_poly_mul(rop->num, op1->num, rop->num);
fmpz_poly_div(rop->den, op1->den, rop->den);
fmpz_poly_mul(rop->den, rop->den, op2->den);
}
}
else
{
fmpz_poly_gcd(rop->den, op2->num, op1->den);
if (fmpz_poly_is_one(rop->den))
{
fmpz_poly_div(rop->den, op2->den, rop->num);
fmpz_poly_mul(rop->den, op1->den, rop->den);
fmpz_poly_div(rop->num, op1->num, rop->num);
fmpz_poly_mul(rop->num, rop->num, op2->num);
}
else
{
fmpz_poly_t t, u;
fmpz_poly_init(t);
fmpz_poly_init(u);
fmpz_poly_div(t, op1->num, rop->num);
fmpz_poly_div(u, op2->den, rop->num);
fmpz_poly_div(rop->num, op2->num, rop->den);
fmpz_poly_mul(rop->num, t, rop->num);
fmpz_poly_div(rop->den, op1->den, rop->den);
fmpz_poly_mul(rop->den, rop->den, u);
fmpz_poly_clear(t);
fmpz_poly_clear(u);
}
}
}
