[Delete k digits] Possible Bug

[OmarElgabry]

Hello!,

I tried to use the code for deleting k digits but it seems it fails in some test cases.

Given num = 891, k =1.
Output 89

I think the correct solution is 81 instead. I've a similar code to get the min/max number by removing k digits, this will return the correct solution.

Please let me know if i'm missing something here.

Thanks