using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^(?:0(?:1(?:2|)|2(?:1|)|)|1(?:0(?:2|)|2(?:0|)|)|2(?:0(?:1|)|1(?:0|)|))$";
string input = @"Should pass:
0
1
2
01
012
120
210
201
102
Should not pass:
101
111
121
0212";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx