public void Run()
{
List <byte[]> oneToNineCombis = CombiUtils.IntCombinations(new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 }, 9);
HashSet <int> products = new HashSet <int>();
int product = 0;
foreach (byte[] pandigital in oneToNineCombis)
{
for (int i = 0; i < 8; i++)
{
int firstInt = Int32.Parse(bytesToString(pandigital.Take(i + 1).ToArray()));
for (int j = i + 1; j < 8; j++)
{
int secondInt = Int32.Parse(bytesToString(pandigital.Skip(i + 1).Take(j - i).ToArray()));
product = Int32.Parse(bytesToString(pandigital.Skip(j + 1).ToArray()));
if (firstInt * secondInt == product && !products.Contains(product))
{
products.Add(product);
}
}
}
}
BigInteger productsSum = products.Sum();
this.result = productsSum.ToString();
}
public void Run()
{
int n = 1, r = 0;
int moreThanAMill = 0;
while (n <= 100)
{
r = 0;
while (n > r)
{
BigInteger combis = CombiUtils.SelectRfromN(n, r);
if (combis >= 1000000)
{
moreThanAMill++;
}
r++;
}
n++;
}
this.result = moreThanAMill.ToString();
}
public void Run()
{
for (int i = 1000; i < 10000; i++)
{
if (Primes.IsPrime(i))
{
byte[] bytes =
{
Byte.Parse(i.ToString()[0].ToString()),
Byte.Parse(i.ToString()[1].ToString()),
Byte.Parse(i.ToString()[2].ToString()),
Byte.Parse(i.ToString()[3].ToString()),
};
List <byte[]> permutations = CombiUtils.IntCombinations(bytes, 4);
List <int> primes = new List <int>();
List <int> solutionPrimes = new List <int>();
foreach (byte[] perm in permutations)
{
int prime = Int32.Parse(bytesToString(perm));
if (Primes.IsPrime(prime))
{
primes.Add(prime);
}
}
primes.Sort();
primes = primes.Where(x => x.ToString().Length == 4).ToList();
for (int firstIndex = 0; firstIndex < primes.Count(); firstIndex++)
{
bool found = false;
int secondIndex = 1;
while (secondIndex < primes.Count())
{
int diff = primes[secondIndex] - primes[firstIndex];
for (int l = primes.Count - 1; l > secondIndex; l--)
{
if (diff == primes[l] - primes[secondIndex] && diff != 0)
{
solutionPrimes.Add(primes[firstIndex]);
solutionPrimes.Add(primes[secondIndex]);
solutionPrimes.Add(primes[l]);
found = true;
break;
}
}
if (found)
{
break;
}
secondIndex++;
}
if (found)
{
break;
}
}
if (solutionPrimes.Count == 3)
{
if (solutionPrimes[1] - solutionPrimes[0] == solutionPrimes[2] - solutionPrimes[1])
{
Console.WriteLine("Prime 1: {0} Prime 2: {1} Prime 3: {2} - Diff value: {3}",
solutionPrimes[0],
solutionPrimes[1],
solutionPrimes[2],
solutionPrimes[2] - primes[1]
);
}
if (solutionPrimes[0] != 1487)
{
this.result = solutionPrimes[0] + "" + solutionPrimes[1] + "" + solutionPrimes[2];
return;
}
}
}
}
}
