param_polynomial.cc

   1 #include "param_polynomial.h"
   2
   3 using std::vector;
   4
   5 /* Expand "polynomial" as a sum of powers of the "nvar" variables,
   6  * and collect the terms in "terms".
   7  */
   8 static void collect_terms(vector<struct param_term> &terms, vector<int> &powers,
   9                             const evalue *polynomial, unsigned nvar)
  10 {
  11         if (EVALUE_IS_ZERO(*polynomial))
  12                 return;
  13
  14         if (value_zero_p(polynomial->d))
  15                 assert(polynomial->x.p->type == ::polynomial);
  16         if (value_notzero_p(polynomial->d) || polynomial->x.p->pos > nvar) {
  17                 struct param_term t;
  18                 t.powers = powers;
  19                 t.coeff = polynomial;
  20                 terms.push_back(t);
  21                 return;
  22         }
  23
  24         for (int i = polynomial->x.p->size-1; i >= 0; --i) {
  25                 powers[polynomial->x.p->pos-1] = i;
  26                 collect_terms(terms, powers, &polynomial->x.p->arr[i], nvar);
  27         }
  28 }
  29
  30 param_polynomial::param_polynomial(const evalue *polynomial, unsigned nvar)
  31 {
  32         vector<int> powers(nvar);
  33         for (int i = 0; i < nvar; ++i)
  34                 powers[i] = 0;
  35         collect_terms(terms, powers, polynomial, nvar);
  36 }
  37
  38 unsigned param_polynomial::degree()
  39 {
  40         unsigned max_degree = 0;
  41
  42         for (int i = 0; i < terms.size(); ++i) {
  43                 int sum = 0;
  44                 for (int j = 0; j < terms[i].powers.size(); ++j)
  45                         sum += terms[i].powers[j];
  46                 if (sum > max_degree)
  47                         max_degree = sum;
  48         }
  49         return max_degree;
  50 }