using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?<!\.)(?:\s([A-Z\u00C0-\u00dd][A-Z\u00C0-\u00dd]*[a-z\u00E0-\u00ff][a-zA-Z\u00C0-\u00ffA-Z]*)|\s(A|O|À)(?=\s|\.))";
string input = @"Usuário Não Autenticado. Contate o ADM. Em Caso De Ou O A. Vou À Bahia. UsuÁrio Não AUtenTicadO. Ok Vamos testa. Contate o ADM. O Padre joão paulo.";
foreach (Match m in Regex.Matches(input, pattern))
{
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