/// <summary>
/// Sum the digits in an integer and check that number for primeness
/// </summary>
/// <param name="num">The number to process</param>
/// <returns>true if the sum of digits is prime, false otherwise</returns>
public static bool SumOfDigitsIsPrime(long num)
{
string StringNum = num.ToString();
long Sum = 0;
foreach (char c in StringNum)
{
Sum += (long)char.GetNumericValue(c);
}//end foreach
return(IsPrimeClass.IsPrime(Sum));
}
/// <summary>
/// Count the number of integers in a list that are palindromes and both the original number and the palindrome are prime.
/// </summary>
/// <param name="list">The list of integers to process</param>
/// <returns>the count</returns>
public static int CountPalindromesWhereBothArePrime(List <long> list)
{
int palindromePrimeCount = 0;
foreach (long num in list)
{
if (IsPrimeClass.IsPrime(num) == true && IsPalindromeClass.IsPalindrome(num) == true)
{
palindromePrimeCount++;
}
}
return(palindromePrimeCount);
}
/// <summary>
/// Build a list of prime numbers.
/// This method will clear the list before adding anything to it.
/// </summary>
/// <param name="primeNumberList">Where to build the list</param>
/// <param name="length">The number of primes to be added to the list, first number must always be 2</param>
/// <remarks>Matt and Ryan</remarks>
public static void BuildPrimeNumberList(List <long> primeNumberList, int length)
{
long num = 2;
int count = 0;
for (int i = 0; i < length; i++)
{
if (IsPrimeClass.IsPrime(num) == true)
{
primeNumberList.Add(num);
//Console.WriteLine(primeNumberList[count]);
count++;
}
num++;
}
}