static IEnumerable <BigInteger> squareDivisor(BigInteger num)
{
var solutions = new BigPrime().Factors(num)
.ToLookup(p => p)
.SelectMany(x => Enumerable.Repeat(x.Key, x.Count() / 2))
.ToList()
.Backtrack(
BigInteger.One,
(prod, item, i) => prod * item,
prod => true
);
solutions.BacktrackingModel = BacktrackingModel.Combination;
solutions.Distinct = true;
solutions.ContinueOnYielded = true;
return(solutions.SelectResults());
}
public BigDivisor(BigInteger num, BigPrime prime)
{
_factors = prime.Factors(num).ToLookup(x => x);
_num = num;
_prime = prime;
}