Ok, would avoid miss using the function next time,

suggestion to solve the kata in some languages(for me is C++ may need this suggestion)
global variable should be avoided.

7^6^5 and 7^6^1 are different

for this problem, I have met it. Try not to use a global variable

mind that 7^6^5 and 7^6^21 is different, see the pattern from 0 to 8 better than just 0-4

suggest print the list content and current power index

I don't want to raise an issue before actually found it bug but...
in C++
I found that the input may not behave as an int list,
as I tried to use a recursion way (pop_back every recurring round, stop at size=0) to solve and print the array size every round, found that the initial size for some case is 0 then will be 2,after going to 0 it will go to other size and decrease to be 0 again, I guess this is which indicated it's a list with list of int?
{{},{a,b},{c...},...}
instead of {a,b,...}
while in python, I didn't observe this problem and have solved the kata

I could pass the test, but it show my code has error in an attempt, any thoughts?