protected override void Solve(out string answer)
{
//Of course we will assume that this number will start with 9
var list = new List <PrimeRep>();
var primeSolver = new PrimeSolver();
var pandigitizer = new Pandigits('1', 7);
long start = 0_000_000;
long count = 7_654_321;
long progressDone = 0;
Parallelization.GetParallelRanges(start, count, 200).ForAll(sequence =>
{
foreach (var num in sequence.Reverse()) // Go from largest to smallest
{
if (pandigitizer.IsPandigital(num))
{
var rep = new PrimeRep(primeSolver, num);
if (rep.IsPrime)
{
if (pandigitizer.IsPandigital(rep.Value))
{
lock (list) list.Add(rep);
//break; //Because this is the largest by definition, no need to search other values.
}
}
}
#region Update progress
lock (this)
{
progressDone++;
if (progressDone % 100_000 == 0)
{
var percent = progressDone * 100.0 / count;
UpdateProgress($"Range {start}-{start + count}: Done {percent}%. Hits: {list.Count}...");
}
}
#endregion
}
});
var maxItem = list.OrderByDescending(x => x.Value);
var finalRep = maxItem.FirstOrDefault(); //If no prime found, this will be 'null'
long value = 0; //Default
if (finalRep != null)
{
value = finalRep.Value; //Override if exists
}
answer = $"Largest n-digit pandigital prime in range {start} - {start+count}: {value}";
}
protected override void Solve(out string answer)
{
Pandigits pandigitizer = new Pandigits('0', 10);
List <NumberRepresentation> pandigitNumbersWithProperty = new List <NumberRepresentation>();
#region Fast - permutation based approach
Permutations <char> permutations = new Permutations <char>();
var list = permutations.GeneratePermutations(new List <char> {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
});
list.AsParallel().ForAll(item =>
{
var numRep = new NumberRepresentation(MoreMath.IntFromDigits(item));
if (pandigitizer.IsPandigital(numRep))
{
if (numRep.IsSubstringDivisible())
{
lock (pandigitNumbersWithProperty)
{
pandigitNumbersWithProperty.Add(numRep);
}
}
}
}
);
#endregion
#region Slow - brute force approach
//long start = 0_000_000_000;
//long count = 9_999_999_999;
//long progressDone = 0;
//Parallelization.GetParallelRanges(start, count, 200).ForAll(sequence =>
//{
// var repSequence = sequence.Select(v => new NumberRepresentation(v));
// foreach (var rep in repSequence)
// {
// if (pandigitizer.IsPandigital(rep))
// {
// if (rep.IsSubstringDivisible())
// {
// lock (pandigitNumbersWithProperty)
// {
// pandigitNumbersWithProperty.Add(rep);
// }
// }
// }
// #region Update progress
// lock (this)
// {
// progressDone++;
// if (progressDone % 1_000_000 == 0)
// {
// var percent = progressDone * 100.0 / count;
// UpdateProgress($"Range {start}-{start + count}: Done {percent}%. Hits: {pandigitNumbersWithProperty.Count}...");
// }
// }
// #endregion
// }
//});
#endregion
var sum = pandigitNumbersWithProperty.Select(rep => rep.Value).Aggregate((total, num) => total + num);
answer = $"Count = {pandigitNumbersWithProperty.Count}, Sum = {sum}";
}