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Attach every last letter of the word with the next word in C#

There is an interview question that asks me to attach every last letter of the word with the next word in C#. For example the input is "Hey hello world" and the output should be "He yhell oworld".
I've come up with the code below but is there a better way to do this? Perhaps in LINQ?
string inputString = "Hey Hello World";
string[] stringArray = inputString.Split(' ').ToArray();
StringBuilder resultString = new StringBuilder("");
StringBuilder lastLetter = new StringBuilder("");
for (int i = 0; i < stringArray.Length; i++)
{
string temp = stringArray[i].ToString();
if (i < stringArray.Length - 2)
{
resultString.Append(lastLetter + temp.Substring(0, temp.Length - 1));
lastLetter.Clear();
lastLetter.Append(" " + temp.Substring(temp.Length - 1, 1));
}
else
resultString.Append(lastLetter + temp.Substring(0, temp.Length));
}
Console.WriteLine(resultString);

How about using regex
var newtext = Regex.Replace("Hey hello world", #"(.) "," $1");

You are unnecessarily complicating the code. Simply replace space with previous character.
var input = "Hey Hello world";
var arr = input.Trim().ToCharArray();
for(int i =0; i< arr.Length; i++)
{
if(arr[i]==' ')
{
var temp = arr[i];
arr[i] = arr[i - 1];
arr[i - 1] = temp;
}
}
Console.WriteLine(arr);

Here's a LINQ solution, since that seems to be what the OP is looking for.
using System;
using System.Linq;
public class Program
{
const char space = ' ';
public static string DoHomework(string input)
{
return new string
(
input.Select( (c,i) =>
{
if (i == 0 || i == input.Length-1) return c;
if (c == space) return input[i-1];
if (input[i+1] == space) return space;
return c;
}).ToArray()
);
}
public static void Main()
{
var input = "Hey hello world";
var output = DoHomework(input);
Console.WriteLine(output);
}
}
Output:
He yhell oworld
Try it out on DotNetFiddle

Diff comparison word by word and display changes

Could be marked as duplicated, but I haven't found a propper solution yet.
I need to write a function that compares 2 pieces of text word by word, and prints out the text showing added/deleted/changed words. For example:
StringOriginal = "I am Tim and I am 27 years old"
StringEdited = "I am Kim and I am not that old".
Result: I am Tim Kim and I am 27 years not that old.
Most of the diff algorithms I find tend to compare char by char. this works fine, untill you have a 2 different words on the same index, with mutual chars.
"I am Tim" edited to
"I am Kim"
Results into:
I am TKim
instead of
I am Tim Kim.
Any pointers?

Split by space both StringOriginal and StringEdited. Loop thru each word of StringOriginal comparing it to the same word index from Edited. Every unequal word should be put to a temporary variable and concatenate it to the result only when you get equal word again from the loop. Use StringBuilder in creating the result. Hope this helps

Split both strings by space, join the resulting arrays via Union, then back to string like this:
string[] arr1 = str1.Split(' ');
string[] arr2 = str1.Split(' ');
var merged = arr1.Union(arr2).ToArray<string>();
var mergedString = string.Join(' ', merged);

little bit old fashion, but you can try this.
string StringOriginal = "I am Tim and I am 27 years old";
string StringEdited = "I am Kim and I am not that old";
string[] StringOriginalArray = StringOriginal.Split();
string[] StringEditedArray = StringEdited.Split();
string[] newStringArray = new string[StringOriginalArray.Length + StringEditedArray.Length];
int i = 0;
int io = 0;
int ie = 0;
while (i < newStringArray.Length)
{
if (io < StringOriginalArray.Length)
{
newStringArray[i] = StringOriginalArray[io];
io++;
i++;
}
if (ie < StringEditedArray.Length)
{
newStringArray[i] = StringEditedArray[ie];
ie++;
i++;
}
}
string[] finalArray = new string[newStringArray.Length];
int f = 0;
for (int k = 0; k < newStringArray.Length; k=k+2)
{
finalArray[f++] = newStringArray[k];
if (newStringArray[k] != newStringArray[k+1])
{
finalArray[f++] = newStringArray[k+1];
}
}
Console.WriteLine(String.Join(" ", finalArray));
Output:
"I am Tim Kim and I am 27 not years that old"

been looking for an answer myself to this question.
haven't been able to find a good solution.
came up with the following. but it's not perfect.
public static class DiffEngine
{
private static Regex r = new Regex(#"(?<=[\s])", RegexOptions.Compiled);
public static string Process(ref string TextA, ref string TextB)
{
var A = r.Split(TextA);
var B = r.Split(TextB);
var max = Math.Max(A.Count(), B.Count());
var sbDel = new StringBuilder("<del>");
var sbIns = new StringBuilder("<ins>");
var sbOutput = new StringBuilder();
var aCurr = string.Empty;
var bCurr = string.Empty;
var aNext = string.Empty;
var bNext = string.Empty;
for (int i = 0; i < max; i++)
{
aCurr = (i > A.Count() - 1) ? string.Empty : A[i];
bCurr = (i > B.Count() - 1) ? string.Empty : B[i];
aNext = (i > A.Count() - 2) ? string.Empty : A[i + 1];
bNext = (i > B.Count() - 2) ? string.Empty : B[i + 1];
if (aCurr == bCurr)
{
sbOutput.Append(aCurr);
}
else
{
if (aNext != bNext)
{
sbDel.Append(aCurr);
sbIns.Append(bCurr);
}
else
{
sbDel.Append(aCurr);
sbIns.Append(bCurr);
sbOutput
.Append(sbDel.ToString())
.Append("</del>")
.Append(sbIns.ToString())
.Append("</ins>");
sbDel.Clear().Append("<del>");
sbIns.Clear().Append("<ins>");
}
}
}
A = null;
B = null;
sbDel = null;
sbIns = null;
return sbOutput.ToString();
}
}

Split string by character count and store in string array [duplicate]

This question already has answers here:
Splitting a string into chunks of a certain size
(39 answers)
Split string after certain character count
(4 answers)
Closed 8 years ago.
I have a string like this
abcdefghij
And I wast to split this string by 3 characters each.
My desired output will be a string array containing this
abc
def
ghi
j
Is is possible using string.Split() method?

This code will group the chars in groups of 3, and convert each group to a string.
string s = "abcdefghij";
var split = s.Select((c, index) => new {c, index})
.GroupBy(x => x.index/3)
.Select(group => group.Select(elem => elem.c))
.Select(chars => new string(chars.ToArray()));
foreach (var str in split)
Console.WriteLine(str);
prints
abc
def
ghi
j
Fiddle: http://dotnetfiddle.net/1PgFu7

Using a bit of Linq
static IEnumerable<string> Split(string str)
{
while (str.Length > 0)
{
yield return new string(str.Take(3).ToArray());
str = new string(str.Skip(3).ToArray());
}
}
Here is the Demo

IEnumerable<string> GetNextChars ( string str, int iterateCount )
{
var words = new List<string>();
for ( int i = 0; i < str.Length; i += iterateCount )
if ( str.Length - i >= iterateCount ) words.Add(str.Substring(i, iterateCount));
else words.Add(str.Substring(i, str.Length - i));
return words;
}
This will avoid ArgumentOutOfRangeException in #Sajeetharan's answer.
Edit: Sorry for completely dumb previous answer of mine :) this is supposed to do the trick.

No, I don't believe it is possible using just string.Split(). But it is simple enough to create your own function...
string[] MySplit(string input)
{
List<string> results = new List<string>();
int count = 0;
string temp = "";
foreach(char c in input)
{
temp += c;
count++;
if(count == 3)
{
result.Add(temp);
temp = "";
count = 0;
}
}
if(temp != "")
result.Add(temp);
return result.ToArray();
}

IEnumerable<string> Split(string str) {
for (int i = 0; i < str.Length; i += 3)
yield return str.Substring(i, Math.Min(str.Length - i, 3));
}

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);
}

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...