what's wrong here?

Question

https://www.codewars.com/kata/55983863da40caa2c900004e/train/cpp

https://code.sololearn.com/c8PT6muzHMvV/?ref=app

Answer 1

The first thing that i noticed is that you access to items-unallocated vector with

digits[k] = n2 % 10;

you have to do digits.push_back because you dont allocated the space for the items

Answer 2

thanks, but it still doesn't work

Answer 3

Different approach here.
https://code.sololearn.com/cedLjOFg5aYR/?ref=app

Answer 4

Better approach
https://code.sololearn.com/ctzeVloZzdw7/?ref=app