using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"\b(longword1|longword2)\b.*?\b(?!\1\b)(?1)\b";
string input = @"A longword1 B longword2 C
^-------------------^
A longword2 B longword1 C
^-------------------^
while these shouldn't:
A longword1 B longword1 C
A longword2 B longword2 C
A longword1 B
A longword2 C";
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