using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?:^(?=(?:.+\R){4,}.+(?:\R^$|\Z)).{4}\K.{2} | \G(?=(?:.+\R){4,}.+(?:\R^$|\Z)).+\K.{2}(?=.{4}$))
| ^(?=(?:.+\R){3}.+(?:\R^$|\Z)).{2} | \G(?=(?:.+\R){3}.+(?:\R^$|\Z)).+\K.{2}(?=$)
| ^(?=(?:.+\R){2}.+(?:\R^$|\Z)).\K.{2} | \G(?=(?:.+\R){2}.+(?:\R^$|\Z)).+\K.{2}(?=.$)
| ^(?=(?:.+\R).+(?:\R^$|\Z)).{2}\K.{2} | \G(?=(?:.+\R).+(?:\R^$|\Z)).+\K.{2}(?=.{2}$)
| ^(?=(?:.+(?:\R^$|\Z))).{3}\K.+(?=.{3}(?:\R^$|\Z))";
string input = @"aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaa
sdaffdsdfsdsfaadd
afdsafdsfssdsfdfs
afdsfdssdfdssfdsf
asfddsfafsdfdsdsf
asfdsdfafdsafasdf
hellohellohellohellohello
hellohellohellohellohello
hellohellohellohellohello
hellohellohellohellohello
hellohellohellohellohello
hellohellohellohellohello
";
RegexOptions options = RegexOptions.Multiline | RegexOptions.IgnorePatternWhitespace;
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