public void UniqueCharacters()
 {
     Assert.IsTrue(uniqueCharacters.IsUnique("ab"));
     Assert.IsFalse(uniqueCharacters.IsUnique("aa"));
     Assert.IsTrue(uniqueCharacters.IsUnique("abcdefghijklmopqrtsuvwxyz"));
     Assert.IsFalse(uniqueCharacters.IsUnique("mama"));
 }
 public static void Run()
 {
     string[] words = { "abcd", "aabc", "xycc" };
     foreach (var word in words)
     {
         Console.WriteLine(word + " " + UniqueCharacters.IsUnique(word));
         Console.WriteLine(word + " " + UniqueCharacters.IsUnique2(word));
     }
     //Console.Read();
 }