using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(((?:[+\-\/*]6+|6+[+\-\/*]|([^6]|\b)6{1,2}(?3)|(?3)6{6,}(?3)|[0-57-9]6+|6+[0-57-9])(*SKIP)(*F))|6)";
string substitution = @"六";
string input = @"66
老铁666这类的， 6666
三到五个六66666
5666有其他数字不替换
6665
566665
666666
66
+66
666-
";
RegexOptions options = RegexOptions.Multiline;
Regex regex = new Regex(pattern, options);
string result = regex.Replace(input, substitution);
}
}
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