// P-3 MCS 360 due Mon 25 Oct 2010 : poly.tc

#include <sstream>
#include "poly.h"
#include <list>

template <typename T>
Poly<T>::Poly(T c, int d)
{
   Monomial m;
   m.coeff = c;
   m.deg = d;
   p.push_back(m);
}

template <typename T>
std::string Poly<T>::to_string()
{
   std::ostringstream s;

   if(p.empty())
      s << "0";
   else
   {
      typename std::list<Monomial>::iterator i;
      bool first = true;

      i = p.begin();
      while(i != p.end())  
      {
         Monomial m = *i++;
         if(first) 
            first = false;
         else
            if(m.coeff > 0) s << "+";
         s << m.coeff << "*" << "x^" << m.deg;
      }
   }
   return s.str();
}

template <typename T>
void Poly<T>::add_monomial(const Monomial m)
{
   typename std::list<Monomial>::iterator i;
   bool done = false;

   i = p.begin();
   while(i != p.end())
   {
      Monomial a = *i;
      if(a.deg == m.deg)
      {
         i->coeff = a.coeff + m.coeff;
         if(i->coeff == 0) i = p.erase(i);
         done = true;
      }
      if(done) break;
      i++;
   }
   if(!done) this->p.push_back(m);
}

template <typename T>
Poly<T> Poly<T>::operator+(const Poly<T>& other)
{
   Poly<T> r = *this;

   std::list<Monomial> L = other.p;

   while(!L.empty())
   { 
      Monomial m = L.front();
      r.add_monomial(m);
      L.pop_front();
   }
   return r;
}