Polynomial::Polynomial(const Polynomial& that)
: numVars_(that.numVars_) {
PowersToCoeffMap::const_iterator iter;
for (iter = that.terms_.begin(); iter != that.terms_.end(); ++iter) {
assert(hasSameNumVars(iter->first));
assert(isValidCoeff(iter->second));
terms_.insert(PowersToCoeffMap::value_type(iter->first, iter->second));
}
assert(getNumTerms() == that.getNumTerms());
}
// O(n^2) factoring
void Polynomial::factor()
{
/*
PRE-CONDITIONS:
The polynomial is of the correct format.
POST-CONDITIONS:
The polynomial will combine all like terms in preparation for either output or addition.
*/
Polynomial newPoly;
Term currentTerm;
int newCoefficient;
// Loop while there is a term left to check
while (termList.size() > 0)
{
bool foundLikeTerm = false;
// If there are no terms in the new polynomial add the first term
if (newPoly.getNumTerms() == 0)
{
// If the exponent is anything but 0, add the term as is.
if (termList.front().getExponent() != 0)
{
newPoly.addTermToList(termList.front());
termList.pop_front();
}
else{
// If the exponent is zero, drop the variable and add the coefficient
newPoly.addTermToList(Term(termList.front().getCoefficient()));
termList.pop_front();
}
}
else
{
// Set new current term to be checked against the new polynomial
currentTerm = termList.front();
// If the exponent of the term is zero, drop the variable
if (currentTerm.getExponent() == 0)
currentTerm = Term(termList.front().getCoefficient());
// Iterate through the new polynomial to check for matches of exponents
// If the exponents match add the terms together, else add to the end of the new poly
for (list<Term>::iterator iter = newPoly.termList.begin(); iter != newPoly.termList.end();)
{
// If the exponents match or they are both numbers with no variables, add them together
if ((iter->getExponent() == currentTerm.getExponent()) || (iter->getHasVariable() == false && currentTerm.getHasVariable() == false))
{
newCoefficient = iter->getCoefficient() + currentTerm.getCoefficient();
iter->setCoefficient(newCoefficient);
foundLikeTerm = true;
break;
}
else{
// Advance iterator if no matches are found on the current term
iter++;
}
}
// If it gets through the new poly without a match, add it to the new poly
if(foundLikeTerm == false)
newPoly.addTermToList(currentTerm);
termList.pop_front();
}
}
// Clear everything from old polynomial, update with the new polynomial
termList = newPoly.termList;
}