public override Term CheckAddReduce(Term t)
{
if (t.GetType() == typeof(Multiplication))
{
Multiplication cMult = (Multiplication)t;
List <Term> a = Parameters.ToList(), b = cMult.Parameters.ToList();
List <Term> commonTerms = new List <Term>();
for (int i = 0; i < a.Count; i++)
{
for (int k = 0; k < b.Count; k++)
{
if (a[i] == b[k])
{
commonTerms.Add(a[i]);
a.RemoveAt(i);
b.RemoveAt(k);
i--;
break;
}
}
}
if (a.Count == 0)
{
a.Add(1);
}
if (b.Count == 0)
{
a.Add(1);
}
commonTerms.Add(new Addition((a.Count == 1) ? a[0] : new Multiplication(a.ToArray()), (b.Count == 1) ? b[0] : new Multiplication(b.ToArray())).Reduce());
for (int i = 0; i < commonTerms.Count; i++)
{
if (commonTerms[i].GetType() == typeof(Real) && ((Real)commonTerms[i]).Value == 0)
{
return(0);
}
}
if (commonTerms.Count == 1)
{
Term term = commonTerms[0];
if (IsMulInverse)
{
term.IsMulInverse = !commonTerms[0].IsMulInverse;
}
if (IsMulInverse)
{
term.IsAddInverse = !commonTerms[0].IsAddInverse;
}
return(term);
}
return(new Multiplication(IsAddInverse, IsMulInverse, commonTerms.ToArray()));
}
if (Parameters.Any(x => x == t))
{
IEnumerable <Term> terms = Parameters.Where(x => x != t);
return(new Multiplication(IsAddInverse, IsMulInverse, t, new Addition(terms.Count() > 1 ? new Multiplication(terms.ToArray()) : terms.First(), 1).Reduce()));
}
return(null);
}
public override Term Reduce()
{
List <Term> paras = Parameters.Select(x => x.Reduce()).Where(x => !x.IsOne()).ToList();
if (paras.Where(x => x.IsZero()).Count() > 0)
{
return(0);
}
// merge branches
for (int i = 0; i < paras.Count; i++)
{
if (paras[i].GetType() == typeof(Multiplication))
{
paras.AddRange(((Multiplication)paras[i]).Parameters);
paras.RemoveAt(i);
}
}
// extract sign
bool isAddInverse = IsAddInverse;
foreach (Term t in paras)
{
if (t.IsAddInverse)
{
isAddInverse = !isAddInverse;
}
}
// merge powers
List <(Term b, Term p)> powerCounter = new List <(Term, Term)>();
for (int i = 0; i < paras.Count; i++)
{
if (paras[i].GetType() == typeof(Real))
{
continue;
}
if (paras[i].GetType() == typeof(Power))
{
Power p = paras[i] as Power;
int index = powerCounter.FindIndex(x => x.b == p.Parameters[0]);
if (index > -1)
{
if (paras[i].IsMulInverse)
{
powerCounter[index] = (powerCounter[index].b, powerCounter[index].p - p.Parameters[1]);
}
else
{
powerCounter[index] = (powerCounter[index].b, powerCounter[index].p + p.Parameters[1]);
}
}
else
{
if (p.IsMulInverse)
{
powerCounter.Add((p.Parameters[0], -p.Parameters[1]));
}
else
{
powerCounter.Add((p.Parameters[0], p.Parameters[1]));
}
}
}
else
{
int index = powerCounter.FindIndex(x => x.b == paras[i]);
if (index > -1)
{
if (paras[i].IsMulInverse)
{
powerCounter[index] = (powerCounter[index].b, powerCounter[index].p - new Real(1));
}
else
{
powerCounter[index] = (powerCounter[index].b, powerCounter[index].p + new Real(1));
}
}
else
{
if (paras[i].IsMulInverse)
{
powerCounter.Add((paras[i], -new Real(1)));
}
else
{
powerCounter.Add((paras[i], new Real(1)));
}
}
}
}
double real = 1;
foreach (Real r in paras.Where(x => x.GetType() == typeof(Real)).Cast <Real>())
{
if (r.IsMulInverse)
{
real /= r.Value;
}
else
{
real *= r.Value;
}
}
if (real != 1)
{
powerCounter.Add((new Real(real), 1));
}
List <Term> reducedTerms = new List <Term>();
foreach ((Term b, Term p)powerPair in powerCounter)
{
Term p = powerPair.p.Reduce();
Term b = powerPair.b.Clone();
if (p.IsOne())
{
b.IsAddInverse = false;
b.IsMulInverse = p.IsAddInverse;
reducedTerms.Add(b);
}
else
{
b.IsMulInverse = false;
b.IsAddInverse = false;
if (p.IsAddInverse)
{
reducedTerms.Add(new Power(false, true, b, p));
}
else
{
reducedTerms.Add(new Power(false, false, b, p));
}
}
}
switch (reducedTerms.Count)
{
case 0: return(1);
case 1:
if (reducedTerms[0].IsMulInverse)
{
return(new Multiplication(IsAddInverse, IsMulInverse, 1, reducedTerms[0]));
}
else
{
return(reducedTerms[0]);
}
default: return(new Multiplication(IsAddInverse, IsMulInverse, reducedTerms.ToArray()));
}
}