void polynomial_print(const Polynomial* polynomial, int newline) {
assert(polynomial != NULL);
printf("(");
Monomial *current = polynomial->first;
while(current != NULL) {
monomial_print(current);
current = monomial_get_next(current);
if(current != NULL) {
printf(", ");
}
}
printf(")");
if(newline) {
printf("\n");
}
}
/**
* Extracts the largest monomial power out of P and Q and into gcd, also divide.
* For example, P and Q in Z[y, x]
*
* P = 4*y*x^2 + 2*y^2 = 2*y^2*(2*x^2 + 1)
* Q = 2*y^3*x^3
*
* gives
*
* gcd = 2*y^2
* P = 2*x^2 + 1
* Q = 2*y*x^3
*/
void coefficient_gcd_monomial_extract(const lp_polynomial_context_t* ctx, coefficient_t* gcd, coefficient_t* P, coefficient_t* Q) {
TRACE("coefficient", "coefficient_gcd_monomial_extract()\n");
if (trace_is_enabled("coefficient")) {
tracef("P = "); coefficient_print(ctx, P, trace_out); tracef("\n");
tracef("Q = "); coefficient_print(ctx, Q, trace_out); tracef("\n");
}
assert(P != Q);
lp_monomial_t m_P_gcd, m_Q_gcd, m_tmp;
lp_monomial_construct(ctx, &m_P_gcd);
lp_monomial_construct(ctx, &m_Q_gcd);
lp_monomial_construct(ctx, &m_tmp);
// Compute the gcd
coefficient_traverse(ctx, P, monomial_gcd_visit, &m_tmp, &m_P_gcd);
lp_monomial_clear(ctx, &m_tmp);
coefficient_traverse(ctx, Q, monomial_gcd_visit, &m_tmp, &m_Q_gcd);
if (trace_is_enabled("coefficient")) {
tracef("P_gcd = "); monomial_print(ctx, &m_P_gcd, trace_out); tracef("\n");
tracef("Q_gcd = "); monomial_print(ctx, &m_Q_gcd, trace_out); tracef("\n");
}
// Final gcd
lp_monomial_t m_gcd;
lp_monomial_construct(ctx, &m_gcd);
lp_monomial_gcd(ctx, &m_gcd, &m_P_gcd, &m_Q_gcd);
// Construct the result
coefficient_t result;
coefficient_construct(ctx, &result);
coefficient_add_ordered_monomial(ctx, &m_gcd, &result);
// Divide P and Q with their gcds
coefficient_t P_gcd, Q_gcd;
coefficient_construct(ctx, &P_gcd);
coefficient_construct(ctx, &Q_gcd);
coefficient_add_ordered_monomial(ctx, &m_P_gcd, &P_gcd);
coefficient_add_ordered_monomial(ctx, &m_Q_gcd, &Q_gcd);
coefficient_div(ctx, P, P, &P_gcd);
coefficient_div(ctx, Q, Q, &Q_gcd);
coefficient_destruct(&P_gcd);
coefficient_destruct(&Q_gcd);
// Output the result
coefficient_swap(&result, gcd);
coefficient_destruct(&result);
lp_monomial_destruct(&m_gcd);
lp_monomial_destruct(&m_tmp);
lp_monomial_destruct(&m_Q_gcd);
lp_monomial_destruct(&m_P_gcd);
if (trace_is_enabled("coefficient")) {
tracef("coefficient_gcd_monomial_extract() =>"); coefficient_print(ctx, gcd, trace_out); tracef("\n");
tracef("P = "); coefficient_print(ctx, P, trace_out); tracef("\n");
tracef("Q = "); coefficient_print(ctx, Q, trace_out); tracef("\n");
}
}
