public void WhenNullShouldBeEmptyArray()
{
var sut = new Anagram();
var expected = new string[]{};
var actual = sut.Generate(null);
Assert.AreEqual(expected, actual);
}
public void WhenTwoLettersShouldBeTwoLetterArray()
{
var sut = new Anagram();
var anonymous = "ab";
var expected = new string[]{"ab","ba"};
var actual = sut.Generate(anonymous);
Assert.AreEqual(expected, actual);
}
public void WhenSingleLetterShouldBeOneMemberArray()
{
var sut = new Anagram();
var anonymous = "a";
var expected = new string[]{anonymous};
var actual = sut.Generate(anonymous);
Assert.AreEqual(expected, actual);
}
public void WhenManyLettersShouldGenerateAnagrams()
{
var sut = new Anagram();
var anonymous = "biro";
var expected = new string[]{"biro","bior","brio","broi","boir","bori",
"ibro","ibor","irbo","irob","iobr","iorb",
"rbio","rboi","ribo","riob","robi","roib",
"obir","obri","oibr","oirb","orbi","orib"};
var actual = sut.Generate(anonymous);
Assert.AreEqual(expected, actual);
}
public static List <string> Of(string s)
{
if (s.Length <= 1)
{
return new List <string> {
s
}
}
;
var anagrams = new List <string>();
for (var i = 0; i < s.Length; i++)
{
var droppedCharacter = s.Substring(i, 1);
var anagramsOfRest = Anagram.Of(DropCharacter(s, i));
foreach (var anagramOfRest in anagramsOfRest)
{
anagrams.Add(droppedCharacter + anagramOfRest);
}
}
return(anagrams);
}