Created
September 7, 2015 19:33
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| using System; | |
| using System.Collections.Generic; | |
| using System.Linq; | |
| using System.Text.RegularExpressions; | |
| namespace Crux.Core.Types | |
| { | |
| //Hexavigesimal number system A = 1 ... Z = 26, AA = 27 ... | |
| public class Base26 | |
| { | |
| private const string Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; | |
| public string AlphaNumber { get; } | |
| public int DecimalNumber { get; } | |
| public Base26(int decimalNumber) | |
| { | |
| if (decimalNumber <= 0) throw new ArgumentException("decimalNumber cannot be 0 or negative"); | |
| AlphaNumber = ToAlphaNumber(decimalNumber); | |
| DecimalNumber = decimalNumber; | |
| } | |
| public Base26(string alphaNumber) | |
| { | |
| alphaNumber = alphaNumber.ToUpper(); | |
| Validate(alphaNumber); | |
| DecimalNumber = ToDecimal(alphaNumber); | |
| AlphaNumber = alphaNumber; | |
| } | |
| private static void Validate(string alphaNumber) | |
| { | |
| var conditions = new Func<string, bool>[] { | |
| string.IsNullOrWhiteSpace, | |
| s => !Regex.IsMatch(s, "^[a-zA-Z]+$") | |
| }; | |
| if (conditions.Any(c => c(alphaNumber))) { | |
| throw new ArgumentException($"{alphaNumber} is not a valid alphaNumber"); | |
| } | |
| } | |
| private static int ToDecimal(string alphaNumber) | |
| { | |
| try { | |
| return alphaNumber | |
| .Reverse() | |
| .Select((c, i) => (int)(ToDecimal(c) * Math.Pow(26, i))) | |
| .Sum(); | |
| } | |
| catch (OverflowException) { | |
| throw new ArgumentException("alphaNumber given is outside of the range of the integer type"); | |
| } | |
| } | |
| private static string ToAlphaNumber(int decimalNumber) | |
| { | |
| var remainders = new List<int>(); | |
| var remainder = 0; | |
| for (var counter = 1; remainder != decimalNumber; counter++) | |
| { | |
| remainder = decimalNumber % (int)(Math.Pow(26, counter)); | |
| remainders.Add(remainder); | |
| } | |
| var characters = remainders | |
| .Select((r, i) => ToChar((int)Math.Floor(r / (Math.Pow(26, i))))) | |
| .Reverse(); | |
| return string.Join(string.Empty, characters); | |
| } | |
| private static int ToDecimal(char c) | |
| { | |
| return Alphabet.IndexOf(c) + 1; | |
| } | |
| private static char ToChar(int decimalNumber) | |
| { | |
| return Alphabet[decimalNumber - 1]; | |
| } | |
| #region Overrides and Overloads | |
| public static explicit operator string(Base26 base26) | |
| { | |
| return base26.AlphaNumber; | |
| } | |
| public static explicit operator int (Base26 base26) | |
| { | |
| return base26.DecimalNumber; | |
| } | |
| public static explicit operator Base26(int decimalNumber) | |
| { | |
| return new Base26(decimalNumber); | |
| } | |
| public static explicit operator Base26(string alphaNumber) | |
| { | |
| return new Base26(alphaNumber); | |
| } | |
| public static Base26 operator + (Base26 a, Base26 b) | |
| { | |
| return new Base26(a.DecimalNumber + b.DecimalNumber); | |
| } | |
| public static Base26 operator - (Base26 a, Base26 b) | |
| { | |
| return new Base26(a.DecimalNumber - b.DecimalNumber); | |
| } | |
| public static Base26 operator * (Base26 a, Base26 b) | |
| { | |
| return new Base26(a.DecimalNumber * b.DecimalNumber); | |
| } | |
| public static Base26 operator / (Base26 a, Base26 b) | |
| { | |
| return new Base26(a.DecimalNumber / b.DecimalNumber); | |
| } | |
| protected bool Equals(Base26 other) | |
| { | |
| return string.Equals(AlphaNumber, other.AlphaNumber) && DecimalNumber == other.DecimalNumber; | |
| } | |
| public override bool Equals(object obj) | |
| { | |
| if (ReferenceEquals(null, obj)) | |
| { | |
| return false; | |
| } | |
| if (ReferenceEquals(this, obj)) | |
| { | |
| return true; | |
| } | |
| if (obj.GetType() != GetType()) | |
| { | |
| return false; | |
| } | |
| return Equals((Base26)obj); | |
| } | |
| public override int GetHashCode() | |
| { | |
| unchecked | |
| { | |
| return ((AlphaNumber != null ? AlphaNumber.GetHashCode() : 0) * 397) ^ DecimalNumber; | |
| } | |
| } | |
| #endregion | |
| } | |
| } |
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Hi - there are some problems with this implementation. For instance AAAA isn't a valid Hexavigesimal number. Hexavigesimal would wrap from ZZZ to BAAA. In the same way 0000 isn't a valid number.