/// <summary>
/// https://projecteuler.net/problem=61
/// </summary>
/// <param name="arguments"></param>
/// <returns></returns>
public static Result CyclicalFigurateNumbers(Problem arguments)
{
var numbers = UtilityMath.GetPolygonalNumbers <int>(1009, 9999).ToArray();
var count = numbers.Length;
var types = Enumerable.Range(0, count).ToArray <int>(); // array of polygonal number types used
var setNumberOrder = UtilityString.GeneratePermutations <int>(types); // permutation of the types indicat1ing all combinations of these in a sequence of numbers
var s = UtilityMath.GetNumericalCyclicalSet(setNumberOrder, numbers);
var answer = s.set.Sum().ToString();
var message = string.Format("The sum of the only ordered set of six cyclic 4-digit numbers for which each polygonal type: triangle, square, pentagonal, hexagonal, heptagonal, and octagonal, is represented by a different number in the set is {0}.", answer);
if (Answers[arguments.Id] != answer)
{
message += string.Format(" => INCORRECT ({0})", Answers[arguments.Id]);
}
var r = new Result(arguments.Id, message)
{
Answer = answer
};
return(r);
}
//private static double SquareWithConvergence(int n)
//{
// return 1 + 1 / ConergentFraction(n);
// //1 + 1/2
// //1 + 1/(2 + 1/2))
// //1 + 1/(2 + 1/(2 + 1/2)))
//}
private static bool IsLychrel(BigInteger number)
{
var lychrel = number;
for (int i = 0; i < 50; i++)
{
lychrel += lychrel.Reverse();
if (UtilityString.IsPalindrome(lychrel.ToString()))
{
return(false);
}
}
return(true);
}
/// <summary>
/// 获取用DES方法加密 [一个指定的待加密的字符串] 后的字符串
/// </summary>
/// <param name="encryptString">一个指定的待加密的字符串</param>
/// <param name="encryptKey">加密密钥,要求为8位</param>
/// <returns>加密成功返回加密后的字符串,失败返回源串</returns>
public static string DESEncrypt(string encryptString, string encryptKey)
{
encryptKey = UtilityString.GetSubString(encryptKey, 0, 8, "");
encryptKey = encryptKey.PadRight(8, ' ');
byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
byte[] rgbIV = Keys;
byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return(Convert.ToBase64String(mStream.ToArray()));
}
/// <summary>
/// DES解密字符串
/// </summary>
/// <param name="decryptString">待解密的字符串</param>
/// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>
/// <returns>解密成功返回解密后的字符串,失败返源串</returns>
public static string DESDecrypt(string decryptString, string decryptKey)
{
try
{
decryptKey = UtilityString.GetSubString(decryptKey, 0, 8, "");
decryptKey = decryptKey.PadRight(8, ' ');
byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
byte[] rgbIV = Keys;
byte[] inputByteArray = Convert.FromBase64String(decryptString);
DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return(Encoding.UTF8.GetString(mStream.ToArray()));
}
catch
{
return(decryptString);
}
}
public Number(int n)
{
Value = n;
FrequencyMap = UtilityString.GetCharacterFrequencyMap(n.ToString());
Patterns = UtilityMath.GetNumericPatterns(n);
}