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Better way for the special concatenation of two strings

I want to concatenate two strings in such a way, that after the first character of the first string, the first character of second string comes, and then the second character of first string comes and then the second character of the second string comes and so on. Best explained by some example cases:
s1="Mark";
s2="Zukerberg"; //Output=> MZaurkkerberg
if:
s1="Zukerberg";
s2="Mark" //Output=> ZMuakrekrberg
if:
s1="Zukerberg";
s2="Zukerberg"; //Output=> ZZuukkeerrbbeerrgg
I've written the following code which gives the expected output but its seems to be a lot of code. Is there any more efficient way for doing this?
public void SpecialConcat(string s1, string s2)
{
string[] concatArray = new string[s1.Length + s2.Length];
int k = 0;
string final = string.Empty;
string superFinal = string.Empty;
for (int i = 0; i < s1.Length; i++)
{
for (int j = 0; j < s2.Length; j++)
{
if (i == j)
{
concatArray[k] = s1[i].ToString() + s2[j].ToString();
final = string.Join("", concatArray);
}
}
k++;
}
if (s1.Length > s2.Length)
{
string subOne = s1.Remove(0, s2.Length);
superFinal = final + subOne;
}
else if (s2.Length > s1.Length)
{
string subTwo = s2.Remove(0, s1.Length);
superFinal = final + subTwo;
}
else
{
superFinal = final;
}
Response.Write(superFinal);
}
}
I have written the same logic in Javascript also, which works fine but again a lot of code.

var s1 = "Mark";
var s2 = "Zukerberg";
var common = string.Concat(s1.Zip(s2, (a, b) => new[]{a, b}).SelectMany(c => c));
var shortestLength = Math.Min(s1.Length, s2.Length);
var result =
common + s1.Substring(shortestLength) + s2.Substring(shortestLength);

var stringBuilder = new StringBuilder();
for (int i = 0; i < Math.Max(s1.Length, s2.Length); i++)
{
if (i < s1.Length)
stringBuilder.Append(s1[i]);
if (i < s2.Length)
stringBuilder.Append(s2[i]);
}
string result = stringBuilder.ToString();

In JavaScript, when working with strings, you are also working with arrays, so it will be easier. Also + will concatenate for you. Replace string indexing with charAt if you want IE7- support.
Here is the fiddle:
http://jsfiddle.net/z6XLh/1
var s1 = "Mark";
var s2 = "ZuckerFace";
var out ='';
var l = s1.length > s2.length ? s1.length : s2.length
for(var i = 0; i < l; i++) {
if(s1[i]) {
out += s1[i];
}
if(s2[i]){
out += s2[i];
}
}
console.log(out);

static string Join(string a, string b)
{
string returnVal = "";
int length = Math.Min(a.Length, b.Length);
for (int i = 0; i < length; i++)
returnVal += "" + a[i] + b[i];
if (a.Length > length)
returnVal += a.Substring(length);
else if(b.Length > length)
returnVal += b.Substring(length);
return returnVal;
}
Could possibly be improved through stringbuilder

Just for the sake of curiosity, here's an unreadable one-liner (which I have nevertheless split over multiple lines ;))
This uses the fact that padding a string to a certain length does nothing if the string is already at least that length. That means padding each string to the length of the other string will have the result of padding out with spaces the shorter one to the length of the longer one.
Then we use .Zip() to concatenate each of the pairs of characters into a string.
Then we call string.Concat(IEnumerable<string>) to concatenate the zipped strings into a single string.
Finally, we remove the extra padding spaces we introduced earlier by using string.Replace().
var result = string.Concat
(
s1.PadRight(s2.Length)
.Zip
(
s2.PadRight(s1.Length),
(a,b)=>string.Concat(a,b)
)
).Replace(" ", null);
On one line [insert Coding Horror icon here]:
var result = string.Concat(s1.PadRight(s2.Length).Zip(s2.PadRight(s1.Length), (a,b)=>string.Concat(a,b))).Replace(" ", null);

Just off the top of my head, this is how I might do it.
var s1Length = s1.Length;
var s2Length = s2.Length;
var count = 0;
var o = "";
while (s1Length + s2Length > 0) {
if (s1Length > 0) {
s1Length--;
o += s1[count];
}
if (s2Length > 0) {
s2Length--;
o += s2[count];
}
count++;
}

Here's another one-liner:
var s1 = "Mark";
var s2 = "Zukerberg";
var result = string.Join("",
Enumerable.Range(0, s1.Length).ToDictionary(x => x * 2, x => s1[x])
.Concat(Enumerable.Range(0, s2.Length).ToDictionary(x => x * 2+1, x => s2[x]))
.OrderBy(d => d.Key).Select(d => d.Value));
Basically, this converts both strings into dictionaries with keys that will get the resulting string to order itself correctly. The Enumerable range is used to associate an index with each letter in the string. When we store the dictionaries, it multiplies the index on s1 by 2, resulting in <0,M>,<2,a>,<4,r>,<6,k>, and multiplies s2 by 2 then adds 1, resulting in <1,Z>,<3,u>,<5,k>, etc.
Once we have these dictionaries, we combine them with the .Concat and sort them with the .OrderBy,which gives us <0,M>,<1,Z>,<2,a>,<3,u>,... Then we just dump them into the final string with the string.join at the beginning.

Ok, this is the *second shortest solution I could come up with:
public string zip(string s1, string s2)
{
return (string.IsNullOrWhiteSpace(s1+s2))
? (s1[0] + "" + s2[0] + zip(s1.Substring(1) + " ", s2.Substring(1) + " ")).Replace(" ", null)
: "";
}
var result = zip("mark","zukerberg");
Whoops! My original shortest was the same as mark's above...so, second shortest i could come up with! I had hoped I could really trim it down with the recursion, but not so much.

var sWordOne = "mark";// ABCDEF
var sWordTwo = "zukerberg";// 123
var result = (sWordOne.Length > sWordTwo.Length) ? zip(sWordOne, sWordTwo) : zip(sWordTwo, sWordOne);
//result = "zmuakrekrberg"
static string zip(string sBiggerWord, string sSmallerWord)
{
if (sBiggerWord.Length < sSmallerWord.Length) return string.Empty;// Invalid
if (sSmallerWord.Length == 0) sSmallerWord = " ";
return string.IsNullOrEmpty(sBiggerWord) ? string.Empty : (sBiggerWord[0] + "" + sSmallerWord[0] + zip(sBiggerWord.Substring(1),sSmallerWord.Substring(1))).Replace(" ","");
}

A simple alternative without Linq witchcraft:
string Merge(string one, string two)
{
var buffer = new char[one.Length + two.Length];
var length = Math.Max(one.Length, two.Length);
var index = 0;
for (var i = 0; i < length; i ++)
{
if (i < one.Length) buffer[index++] = one[i];
if (i < two.Length) buffer[index++] = two[i];
}
return new string(buffer);
}

C# How can I compare two word strings and indicate which parts are different

For example if I have...
string a = "personil";
string b = "personal";
I would like to get...
string c = "person[i]l";
However it is not necessarily a single character. I could be like this too...
string a = "disfuncshunal";
string b = "dysfunctional";
For this case I would want to get...
string c = "d[isfuncshu]nal";
Another example would be... (Notice that the length of both words are different.)
string a = "parralele";
string b = "parallel";
string c = "par[ralele]";
Another example would be...
string a = "ato";
string b = "auto";
string c = "a[]to";
How would I go about doing this?
Edit: The length of the two strings can be different.
Edit: Added additional examples. Credit goes to user Nenad for asking.

I must be very bored today, but I actually made UnitTest that pass all 4 cases (if you did not add some more in the meantime).
Edit: Added 2 edge cases and fix for them.
Edit2: letters that repeat multiple times (and error on those letters)
[Test]
[TestCase("parralele", "parallel", "par[ralele]")]
[TestCase("personil", "personal", "person[i]l")]
[TestCase("disfuncshunal", "dysfunctional", "d[isfuncshu]nal")]
[TestCase("ato", "auto", "a[]to")]
[TestCase("inactioned", "inaction", "inaction[ed]")]
[TestCase("refraction", "fraction", "[re]fraction")]
[TestCase("adiction", "ad[]diction", "ad[]iction")]
public void CompareStringsTest(string attempted, string correct, string expectedResult)
{
int first = -1, last = -1;
string result = null;
int shorterLength = (attempted.Length < correct.Length ? attempted.Length : correct.Length);
// First - [
for (int i = 0; i < shorterLength; i++)
{
if (correct[i] != attempted[i])
{
first = i;
break;
}
}
// Last - ]
var a = correct.Reverse().ToArray();
var b = attempted.Reverse().ToArray();
for (int i = 0; i < shorterLength; i++)
{
if (a[i] != b[i])
{
last = i;
break;
}
}
if (first == -1 && last == -1)
result = attempted;
else
{
var sb = new StringBuilder();
if (first == -1)
first = shorterLength;
if (last == -1)
last = shorterLength;
// If same letter repeats multiple times (ex: addition)
// and error is on that letter, we have to trim trail.
if (first + last > shorterLength)
last = shorterLength - first;
if (first > 0)
sb.Append(attempted.Substring(0, first));
sb.Append("[");
if (last > -1 && last + first < attempted.Length)
sb.Append(attempted.Substring(first, attempted.Length - last - first));
sb.Append("]");
if (last > 0)
sb.Append(attempted.Substring(attempted.Length - last, last));
result = sb.ToString();
}
Assert.AreEqual(expectedResult, result);
}

Have you tried my DiffLib?
With that library, and the following code (running in LINQPad):
void Main()
{
string a = "disfuncshunal";
string b = "dysfunctional";
var diff = new Diff<char>(a, b);
var result = new StringBuilder();
int index1 = 0;
int index2 = 0;
foreach (var part in diff)
{
if (part.Equal)
result.Append(a.Substring(index1, part.Length1));
else
result.Append("[" + a.Substring(index1, part.Length1) + "]");
index1 += part.Length1;
index2 += part.Length2;
}
result.ToString().Dump();
}
You get this output:
d[i]sfunc[shu]nal
To be honest I don't understand what this gives you, as you seem to completely ignore the changed parts in the b string, only dumping the relevant portions of the a string.

Here is a complete and working console application that will work for both examples you gave:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication2
{
class Program
{
static void Main(string[] args)
{
string a = "disfuncshunal";
string b = "dysfunctional";
StringBuilder sb = new StringBuilder();
for (int i = 0; i < a.Length; i++)
{
if (a[i] != b[i])
{
sb.Append("[");
sb.Append(a[i]);
sb.Append("]");
continue;
}
sb.Append(a[i]);
}
var str = sb.ToString();
var startIndex = str.IndexOf("[");
var endIndex = str.LastIndexOf("]");
var start = str.Substring(0, startIndex + 1);
var mid = str.Substring(startIndex + 1, endIndex - 1);
var end = str.Substring(endIndex);
Console.WriteLine(start + mid.Replace("[", "").Replace("]", "") + end);
}
}
}
it will not work if you want to display more than one entire section of the mismatched word.

You did not specify what to do if the strings were of different lengths, but here is a solution to the problem when the strings are of equal length:
private string Compare(string string1, string string2) {
//This only works if the two strings are the same length..
string output = "";
bool mismatch = false;
for (int i = 0; i < string1.Length; i++) {
char c1 = string1[i];
char c2 = string2[i];
if (c1 == c2) {
if (mismatch) {
output += "]" + c1;
mismatch = false;
} else {
output += c1;
}
} else {
if (mismatch) {
output += c1;
} else {
output += "[" + c1;
mismatch = true;
}
}
}
return output;
}

Not really good approach but as an exercise in using LINQ: task seem to be find matching prefix and suffix for 2 strings, return "prefix + [+ middle of first string + suffix.
So you can match prefix (Zip + TakeWhile(a==b)), than repeat the same for suffix by reversing both strings and reversing result.
var first = "disfuncshunal";
var second = "dysfunctional";
// Prefix
var zipped = first.ToCharArray().Zip(second.ToCharArray(), (f,s)=> new {f,s});
var prefix = string.Join("",
zipped.TakeWhile(c => c.f==c.s).Select(c => c.f));
// Suffix
var zippedReverse = first.ToCharArray().Reverse()
.Zip(second.ToCharArray().Reverse(), (f,s)=> new {f,s});
var suffix = string.Join("",
zippedReverse.TakeWhile(c => c.f==c.s).Reverse().Select(c => c.f));
// Cut and combine.
var middle = first.Substring(prefix.Length,
first.Length - prefix.Length - suffix.Length);
var result = prefix + "[" + middle + "]" + suffix;
Much easier and faster approach is to use 2 for loops (from start to end, and from end to start).

Split a long string to a customized string

Hello I have a long string. I want to split it as some kind of format that has many return carrages.
Each line has 5 short words.
Ex.
string input="'250.0','250.00','250.01','250.02','250.03','250.1','250.10','250.11','250.12','250.13','250.2','250.20','250.21','250.22','250.23','250.3','250.30','250.31','250.32','250.33','250.4','250.40','250.41','250.42','250.43','250.5','250.50','250.51','250.52','250.53','250.6','250.60','250.61','250.62','250.63','250.7','250.70','250.71','250.72','250.73','250.8','250.80','250.81','250.82','250.83','250.9','250.90','250.91','250.92','250.93','357.2','357.20','362.01','362.02','362.03','362.04','362.05','362.06','362.07','366.41','648.0','648.00','648.01','648.02','648.03','648.04'";
It has 66 short words.
string output = "'250.0','250.00','250.01','250.02','250.03',
'250.1','250.10','250.11','250.12','250.13',
'250.2','250.20','250.21','250.22','250.23',
'250.3','250.30','250.31','250.32','250.33',
'250.4','250.40','250.41','250.42','250.43',
'250.5','250.50','250.51','250.52','250.53',
'250.6','250.60','250.61','250.62','250.63',
'250.7','250.70','250.71','250.72','250.73',
'250.8','250.80','250.81','250.82','250.83',
'250.9','250.90','250.91','250.92','250.93',
'357.2','357.20','362.01','362.02','362.03',
'362.04','362.05','362.06','362.07','366.41',
'648.0','648.00','648.01','648.02','648.03',
'648.04'";
I thought that I have to count char ',' in the string first such as in the example. But it could be kind of clumsy.
Thanks for advice.

If i've understood you correctly you want to
split those words by comma
group the result into lines where each line contains 5 words
build a string with Environment.NewLine as separator
string input = "'250.0','250.00','250.01','250.02','250.03','250.1','250.10','250.11','250.12','250.13','250.2','250.20','250.21','250.22','250.23','250.3','250.30','250.31','250.32','250.33','250.4','250.40','250.41','250.42','250.43','250.5','250.50','250.51','250.52','250.53','250.6','250.60','250.61','250.62','250.63','250.7','250.70','250.71','250.72','250.73','250.8','250.80','250.81','250.82','250.83','250.9','250.90','250.91','250.92','250.93','357.2','357.20','362.01','362.02','362.03','362.04','362.05','362.06','362.07','366.41','648.0','648.00','648.01','648.02','648.03','648.04'";
int groupCount = 5;
var linesGroups = input.Split(',')
.Select((s, index) => new { str = s, Position = index / groupCount, Index = index })
.GroupBy(x => x.Position);
StringBuilder outputBuilder = new StringBuilder();
foreach (var grp in linesGroups)
{
outputBuilder.AppendLine(String.Join(",", grp.Select(x => x.str)));
}
String output = outputBuilder.ToString();
Edit: The result is:
'250.0','250.00','250.01','250.02','250.03'
'250.1','250.10','250.11','250.12','250.13'
'250.2','250.20','250.21','250.22','250.23'
'250.3','250.30','250.31','250.32','250.33'
'250.4','250.40','250.41','250.42','250.43'
'250.5','250.50','250.51','250.52','250.53'
'250.6','250.60','250.61','250.62','250.63'
'250.7','250.70','250.71','250.72','250.73'
'250.8','250.80','250.81','250.82','250.83'
'250.9','250.90','250.91','250.92','250.93'
'357.2','357.20','362.01','362.02','362.03'
'362.04','362.05','362.06','362.07','366.41'
'648.0','648.00','648.01','648.02','648.03'
'648.04'
If you want to append every line with a comma(like in your example):
foreach (var grp in linesGroups)
{
outputBuilder.AppendLine(String.Join(",", grp.Select(x => x.str)) + ",");
}
// remove last comma + Environment.NewLine
outputBuilder.Length -= ( 1 + Environment.NewLine.Length );

How about this solution:
private static IEnumerable<string> SplitLongString(string input, char separator, int groupSize)
{
int indexCurrent = 0;
int indexLastOccurence = 0;
int separatorCounter = 0;
foreach (var character in input)
{
indexCurrent++;
if (character == separator)
{
separatorCounter++;
if (separatorCounter % groupSize == 0)
{
yield return input.Substring(indexLastOccurence, indexCurrent - indexLastOccurence);
indexLastOccurence = indexCurrent;
}
}
}
if (indexCurrent != indexLastOccurence)
{
yield return input.Substring(indexLastOccurence, indexCurrent - indexLastOccurence);
}
}
And you would call it:
var result = SplitLongString(input, ',', 5);
foreach (var row in result)
{
Console.WriteLine(row);
}

The simplest way would be to follow the approach from #Tim's deleted (edit: not deleted any more) answer:
Split the string into parts by comma (using string.Split)
Rearrange the obtained parts in any way you need: for example, packing by 5 in a line.
Something like that (not tested):
Console.WriteLine("string output =");
var parts = sourceString.Split(',');
int i = 0;
for (; i < parts.Length; i++)
{
if (i % 5 == 0)
Console.Write(' "');
Console.Write(parts[i]);
Console.Write(',');
if (i % 5 == 4 && i != parts.Length - 1)
Console.WriteLine('" +');
}
Console.WriteLine('";');

var input="'250.0','250.00','250.01','250.02','250.03','250.1','250.10','250.11','250.12','250.13','250.2','250.20','250.21','250.22','250.23','250.3','250.30','250.31','250.32','250.33','250.4','250.40','250.41','250.42','250.43','250.5','250.50','250.51','250.52','250.53','250.6','250.60','250.61','250.62','250.63','250.7','250.70','250.71','250.72','250.73','250.8','250.80','250.81','250.82','250.83','250.9','250.90','250.91','250.92','250.93','357.2','357.20','362.01','362.02','362.03','362.04','362.05','362.06','362.07','366.41','648.0','648.00','648.01','648.02','648.03','648.04'";
var wordsArray = input.Split(',');
var sbOutput = new StringBuilder();
for (int i = 1; i < wordsArray.Length +1; i++)
{
sbOutput.AppendFormat("{0},", wordsArray[i-1]);
if(i % 5 == 0)
sbOutput.AppendLine();
}
var output = sbOutput.ToString();

Do something like this:
string[] words = input.Split(',');
int wordsInString = words.Length;

Concatenate neighboring characters of a special character "-"

i am developing an application using c#.net in which i need that if a input entered by user contains the character '-'(hyphen) then i want the immediate neighbors of the hyphen(-) to be concatenated for example if a user enters
A-B-C then i want it to be replaced with ABC
AB-CD then i want it to be replaced like BC
ABC-D-E then i want it to be replaced like CDE
AB-CD-K then i want it to be replaced like BC and DK both separated by keyword and
after getting this i have to prepare my query to database.
i hope i made the problem clear but if need more clarification let me know.
Any help will be appreciated much.
Thanks,
Devjosh

Use:
string[] input = {
"A-B-C",
"AB-CD",
"ABC-D-E",
"AB-CD-K"
};
var regex = new Regex(#"\w(?=-)|(?<=-)\w", RegexOptions.Compiled);
var result = input.Select(s => string.Concat(regex.Matches(s)
.Cast<Match>().Select(m => m.Value)));
foreach (var s in result)
{
Console.WriteLine(s);
}
Output:
ABC
BC
CDE
BCDK

Untested, but this should do the trick, or at the very least lead you in the right direction.
private string Prepare(string input)
{
StringBuilder output = new StringBuilder();
char[] chars = input.ToCharArray();
for (int i = 0; i < chars.Length; i++)
{
if (chars[i] == '-')
{
if (i > 0)
{
output.Append(chars[i - 1]);
}
if (++i < chars.Length)
{
output.Append(chars[i])
}
else
{
break;
}
}
}
return output.ToString();
}
If you want each pair to form a separate object in an array, try the following code:
private string[] Prepare(string input)
{
List<string> output = new List<string>();
char[] chars = input.ToCharArray();
for (int i = 0; i < chars.Length; i++)
{
if (chars[i] == '-')
{
string o = string.Empty;
if (i > 0)
{
o += chars[i - 1];
}
if (++i < chars.Length)
{
o += chars[i]
}
output.Add(o);
}
}
return output.ToArray();
}

Correct me if I am wrong but surely all you need to do is remove the '-'?
like this:
"A-B-C".Replace("-","");

You can even solve this with a one-liner (although a bit ugly):
String.Join(String.Empty, input.Split('-').Select(q => (q.Length == 0 ? String.Empty : (q.Length > 1 ? (q.First() + q.Last()).ToString() : q.First().ToString())))).Substring(((input[0] + input[1]).ToString().Contains('-') ? 0 : 1), input.Length - ((input[0] + input[1]).ToString().Contains('-') ? 0 : 1) - ((input[input.Length - 1] + input[input.Length - 2]).ToString().Contains('-') ? 0 : 1));
first it splits the string to an array on each '-', then it concatenates only the first and the last character of each string (or just the only character if there's only one, and it leaves the empty string if there's nothing there), and then it concatenates the resulting enumerable to a String. Finally we strip the first and the last letter, if they are not in the needed range.
I know, it's ugly, I'm just saying that it's possible..
Probably it's way better to just use a simple
new Regex(#"\w(?=-)|(?<=-)\w", RegexOptions.Compiled)
and then work with that..
EDIT #Kirill Polishchuk was faster.. his solution should work..
EDIT 2
After the Question has been updated, here's a snippet that should do the trick:
string input = "A-B-C";
string s2;
string s3 = "";
string s4 = "";
var splitted = input.Split('-');
foreach(string s in splitted) {
if (s.Length == 0)
s2 = String.Empty;
else
if (s.Length > 1)
s2 = (s.First() + s.Last()).ToString();
else
s2 = s.First().ToString();
s3 += s4 + s2;
s4 = " and ";
}
int beginning;
int end;
if (input.Length > 1)
{
if ((input[0] + input[1]).ToString().Contains('-'))
beginning = 0;
else
beginning = 1;
if ((input[input.Length - 1] + input[input.Length - 2]).ToString().Contains('-'))
end = 0;
else
end = 1;
}
else
{
if ((input[0]).ToString().Contains('-'))
beginning = 0;
else
beginning = 1;
if ((input[input.Length - 1]).ToString().Contains('-'))
end = 0;
else
end = 1;
}
string result = s3.Substring(beginning, s3.Length - beginning - end);
It's not very elegant, but it should work (not tested though..). it works nearly the same as the one-liner above...

Split a string without separator

I have a string variable with value
"abcdefghijklmnop".
Now I want to split the string into string array with, say, three characters (the last array element may contain fewer) in each array element from the right end.
I.e.,
"a"
"bcd"
"efg"
"hij"
"klm"
"nop"
What is the easiest and simplest way to do this?? (Both Visual Basic and C# code is welcome)?

Here's a solution:
var input = "abcdefghijklmnop";
var result = new List<string>();
int incompleteGroupLength = input.Length % 3;
if (incompleteGroupLength > 0)
result.Add(input.Substring(0, incompleteGroupLength));
for (int i = incompleteGroupLength; i < input.Length; i+=3)
{
result.Add(input.Substring(i, 3));
}
It gives the expected output of:
"a"
"bcd"
"efg"
"hij"
"klm"
"nop"

Here's something that works - wrapped up into a string extension function.
namespace System
{
public static class StringExts
{
public static IEnumerable<string> ReverseCut(this string txt, int cutSize)
{
int first = txt.Length % cutSize;
int taken = 0;
string nextResult = new String(txt.Take(first).ToArray());
taken += first;
do
{
if (nextResult.Length > 0)
yield return nextResult;
nextResult = new String(txt.Skip(taken).Take(cutSize).ToArray());
taken += cutSize;
} while (nextResult.Length == cutSize);
}
}
}
Usage:
textBox2.Text = "";
var txt = textBox1.Text;
foreach (string s in txt.ReverseCut(3))
textBox2.Text += s + "\r\n";

Regex time!!
Regex rx = new Regex("^(.{1,2})??(.{3})*$");
var matches = rx.Matches("abcdefgh");
var pieces = matches[0].Groups[1].Captures.OfType<Capture>().Select(p => p.Value).Concat(matches[0].Groups[2].Captures.OfType<Capture>().Select(p => p.Value)).ToArray();
pieces will contain:
"ab"
"cde"
"fgh"
(Please, don't use this code! It is only an example of what can happen when you use a regular expression + LINQ.)

Well... here is yet another way I arrived at:
private string[] splitIntoAry(string str)
{
string[] temp = new string[(int)Math.Ceiling((double)str.Length / 3)];
while (str != string.Empty)
{
temp[(int)Math.Ceiling((double)str.Length / 3) - 1] = str.Substring(str.Length - Math.Min(str.Length, 3));
str = str.Substring(0, str.Length - Math.Min(str.Length, 3));
}
return temp;
}