Its not I know i'm adding randoms

I created this one as I did not found what I was looking for elsewhere
When a 1 kuy come into a 7 kyu kata just to say that's 'trivial', it does not benefit anybody either.
Maybe you should just relax ?

Don't hesitate to tell me if the task descrption is unclear, i'll update it

I guess the problem may come this line :

long long** result = (long long**)calloc(row, sizeof(long long));

try to declare result as :

long long (*result)[2] = calloc(row, sizeof(lst[0]));

Very efficient solution, indeed, i'm wondering where are defined the lcmu and gdci functions and if we can use them in other katas ?

C translation just Kumited with random tests ;)

Too bad that the answer was NOT the real maximum result you can make with a b and c using + * and ().

By example, here expression_matter(1,3,1) == 5 // 1+3+1
But the real maximum with tose numbers would be 3*(1+1)=6

$ man 3 qsort
This is a quick sorting algorithm, it would prevent you to write the sort(char*,int) function.

This code is very short that is a good point. Unfortunately it's vulnarable to buffer overflows. The output storage 'buffer' is allocated with a fixed size of 500 bytes, checks have to be done to do not exceed this limit.

Concerning the efficiency, the code :

  sprintf(buffer + strlen(buffer), arg);
  j += strlen(arg);

Could be shorten to :

  j += sprintf(buffer + j, arg); // as j is the offset in the buffer, and sprintf returns the # bytes written

We save time by not calling strlen function

And the code :

  arg = va_arg(args, int);
  char* numberBuffer = calloc(10, sizeof(char));
  sprintf(numberBuffer, "%d", arg);
  sprintf(buffer + strlen(buffer), numberBuffer);
  j += strlen(numberBuffer);  

Can be reduced to :

  j += sprintf(buffer + j, "%d", va_arg(args, int));

There is no need here to use dynamic memory, neither to call strlen.

Hope it helps :)