OP solved it, closing

I found it

can someone explain me what does this mean : "When called, the Lift will stop at a floor even if it is full, although unless somebody gets off nobody else can get on!"
I dont get it

@hobovsky Thank you!

Your solution fails one of the sample tests, and you can see sample tests. It crashes on this one:

    Assert::That(determinant(vector< vector<long long> > {
      vector<long long> {1}
    }), Equals(1));

I am using .erase from vector

It's difficult to tell exactly without seeing your code, but it looks like an out-of-bounds read - most probably reading elements out of bounds of a vector, or something like this.

I get this error message although my code works correctly on vs:

UndefinedBehaviorSanitizer:DEADLYSIGNAL ==1==ERROR: UndefinedBehaviorSanitizer: SEGV on unknown address 0x000000000008 (pc 0x000000425762 bp 0x000000000000 sp 0x7ffd80757280 T1) ==1==The signal is caused by a READ memory access. ==1==Hint: address points to the zero page. ==1==WARNING: invalid path to external symbolizer! ==1==WARNING: Failed to use and restart external symbolizer! #0 0x425761 (/workspace/test+0x425761) #1 0x42597b (/workspace/test+0x42597b) #2 0x4286a4 (/workspace/test+0x4286a4) #3 0x426cfe (/workspace/test+0x426cfe) #4 0x426843 (/workspace/test+0x426843) #5 0x42647b (/workspace/test+0x42647b) #6 0x42f045 (/workspace/test+0x42f045) #7 0x425b2d (/workspace/test+0x425b2d) #8 0x7fdd659bfbf6 (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6) #9 0x404709 (/workspace/test+0x404709)

UndefinedBehaviorSanitizer can not provide additional info. ==1==ABORTING

That was funny:)

See @hobosky's comment.

it may happen that the input string have leading, trailing whitespaces and more than a unique whitespace between two consecutive numbers

Maybe it was related to that?

Your solution seems to pass, so I believe you found your mistake?