still possibly useful to someone else reading this in 2 years

It's so cool~

I sure you should consider more carefully that the input maybe is "NONE".

i got the same case. What does it mean?

OK, I need more carefully.

I'm sorry about that. I want to know how to deal it.

I don't know what wrong about my code.

Not a kata issue. Notice at the top of the page that 616 people pased the C++ kata.

UndefinedBehaviorSanitizer:DEADLYSIGNAL
==1==ERROR: UndefinedBehaviorSanitizer: SEGV on unknown address 0x000000000000 (pc 0x000000426c6d bp 0x000000000000 sp 0x7ffc59ac8aa0 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 0x426c6c (/workspace/test+0x426c6c)
#1 0x42a848 (/workspace/test+0x42a848)
#2 0x428a6e (/workspace/test+0x428a6e)
#3 0x42849d (/workspace/test+0x42849d)
#4 0x42818b (/workspace/test+0x42818b)
#5 0x42d165 (/workspace/test+0x42d165)
#6 0x4268cd (/workspace/test+0x4268cd)
#7 0x7f5849ea1bf6 (/lib/x86_64-linux-gnu/libc.so.6+0x21bf6)
#8 0x404af9 (/workspace/test+0x404af9)

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

I had check my ansers, and I don't know what wrong about my code.

I don't get the ku count because of this problem

Not an issue. A mod is looking into it.

I have already submitted of my own code.Later, in order to compare the speed, I tested a code of someone else's 6*6, but I pasted my code and submitted it, only to submit the code of someone else. Is there any way to solve it? I think this is very bad for me, and the code I submitted previously did not add Ku points to me