private static void FindAllSolutions_Recur(int number, int power, SquareStack tmpSolution, List <CandidateSet> candidates = null)
{
if (tmpSolution.GetTopCandidateSum() == number)
{
return;
}
else if (tmpSolution.GetTopCandidateSum() > number)
{
tmpSolution.RemoveTop();
}
if (candidates != null && candidates.All(x => x.IsVisited) && tmpSolution.GetTopCandidateSum() != number)
{
tmpSolution.RemoveTop();
return;
}
int flooredRoot = FlooredRoot(number - tmpSolution.GetTopCandidateSum(), power, tmpSolution.GetTopCandidate());
if (tmpSolution.StackContains(flooredRoot))
{
tmpSolution.RemoveTop();
return;
}
candidates = FindCandidateSet(flooredRoot, tmpSolution.GetTopCandidate());
foreach (CandidateSet candidateSet in candidates.Where(x => x.IsVisited == false).ToList())
{
if (tmpSolution.GetTopCandidate() < candidateSet.Candidate)
{
tmpSolution.RemoveTop();
return;
}
candidateSet.IsVisited = true;
tmpSolution.Add(candidateSet.Candidate, power);
FindAllSolutions_Recur(number, power, tmpSolution, candidates);
if (tmpSolution.GetTopCandidateSum() != number)
{
tmpSolution.RemoveTop();
}
else
{
return;
}
}
}
// best solution ever
public static void FindAllSolutions(int number, int power, List <string> solutions)
{
int flooredRoot = FlooredRoot(number, power);
List <CandidateSet> mainRoots = FindCandidateSet(flooredRoot);
foreach (CandidateSet candidateSet in mainRoots)
{
SquareStack tmpSolution = new SquareStack {
{ candidateSet.Candidate, power, true }
};
FindAllSolutions_Recur(number, power, tmpSolution);
if (tmpSolution.GetTopCandidateSum() == number)
{
string sln = tmpSolution.ToPowerExpression(power);
if (!solutions.Any(x => x.Equals(sln)))
{
solutions.Add(sln);
}
}
}
}