Thank you very much. I have found a nice Linq solution with SingleOrDefault()

the random tests in C# were producing strings that did not conform to the specification: the matrix could have different characters (besides '*') in the same column. My guess is that nobody noticed it until now because most solvers looped from top row to bottom row and exited as soon as a non-'*' was found.

I fixed the C# RNG, and I also added nicer assertion messages that display the input. Your code passes the random tests now. It still fails the edge cases test (empty arrays / empty strings), but that should be an easy fix.

(csharp)I can't find out why the result for this input:

copies=*v*l****, ***l]*W*, +vg*]WWN, +*g****N, *WYhDw*d, 8WYhD*Y*, *WY*Dw*d, 8WYhD*Yd, 8WYh*wYd

should be:

+vgl]WWN

notice: some strings start with '+' und some strings start with '8' and some with '*'

Can someone help me please?

I don't think this is an Issue, since the solution to any kata can be found on the Internet.

When kata authoring is done right, you have a unique problem. Neither the internet nor an AI will know what to do with your kata.

why?

at the end of your for loop, what value does j have ? is it the correct index to nul terminate ? also, notice the warnings:

memset(assembled, '\0', sizeof(assembled));
       ~~~~~~~~~               ^~~~~~~~~
/*
solution.c:9:34:

warning: 'memset' call operates on objects of type 'char' while the size is based on a different type 'char *' [-Wsizeof-pointer-memaccess]
note: did you mean to provide an explicit length?
*/

😂😂😅

(c#): IMHO the example test has still the typo:
Assert.AreEqual("abcde", Kata.Assemble(new string[] {"abcde","abcde","abcbe"}));

c# tests give growing input? every next test is previous+newtest. last test already has 200 lines (all previous lines together)

[Y
yY
ysY
ysY
y*[*

[Y
yY
ysY
ysY
y*[*
PdqTq
PdqTq
dqTq
PqTq
Pdq**

[Y
yY
ysY
ysY
y*[*
PdqTq
PdqTq
dqTq
PqTq
Pdq**
9Mccp
9McWTcp
MWJTcp
9MWJ*p
9McJTp

[Y
yY
ysY
ysY
y*[*
PdqTq
PdqTq
dqTq
PqTq
Pdq**
9Mccp
9McWTcp
MWJTcp
9MWJ*p
9McJTp
2XNs
*2X's
DX'*s
D2X's
D2'Ns

etc.

Approved

Approved

Approved

Can't to approve due to a conflict in the description.
Forks with the correct description for COBOL and Go.

Approved