solve_polynomial_normalization.cpp

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#include "internal/expression_transform.hpp"
#include "internal/symbolic_ast.hpp"
#include "internal/expression_analysis.hpp"
#include "internal/polynomial_solver_support.hpp"
 
namespace LMCAS::polynomial_solver_detail {
 
bool is_purely_numeric(const std::shared_ptr<SymbolicExpr>& expr) {
    return !expr || free_variables(LMCAS::detail::node(expr)).empty();
}
 
std::shared_ptr<SymbolicExpr> negate(const std::shared_ptr<SymbolicExpr>& x) {
    return SymbolicExpr::multiply(SymbolicExpr::number(-1), x);
}
 
std::shared_ptr<SymbolicExpr> sub(const std::shared_ptr<SymbolicExpr>& a, const std::shared_ptr<SymbolicExpr>& b) {
    return SymbolicExpr::add(a, negate(b));
}
 
std::shared_ptr<SymbolicExpr> num(int n) { return SymbolicExpr::number(n); }
 
 
bool convert_to_rational_poly(
    const Polynomial<SymbolicPolyCoeff>& sym_poly,
    Polynomial<Rational>& out_poly, ComputationContext& context)
{
 
    detail::RewriteBudget transform_budget(context, (context).limits().max_recursion_depth,
                                            (context).limits().max_ast_nodes, "transform");
    out_poly = Polynomial<Rational>(sym_poly.variable_name);
    out_poly.coeffs.resize(sym_poly.coeffs.size(), Rational(0));
 
    for (size_t i = 0; i < sym_poly.coeffs.size(); ++i) {
        auto coeff_expr = sym_poly.coeffs[i].val;
        if (!coeff_expr) {
            out_poly.coeffs[i] = Rational(0);
            continue;
        }
 
        auto simplified = detail::make_expression_ptr(detail::normalize_node(detail::node(coeff_expr), transform_budget));
        auto num_node = std::dynamic_pointer_cast<const NumberNode>(
            LMCAS::detail::node(simplified));
        if (!num_node) {
            return false;
        }
        if (std::holds_alternative<Rational>(num_node->value())) {
            out_poly.coeffs[i] = std::get<Rational>(num_node->value());
        } else {
            out_poly.coeffs[i] =
                Rational(std::get<BigInt>(num_node->value()));
        }
    }
 
    out_poly.trim();
    return true;
}
 
}