Need help to optimize my code

Question

https://code.sololearn.com/cuaeNp2cIEtB/?ref=app
I got AC when time limit is 0.4 s
But then the time limit become 0.28 s and i got TLE
Can anyone help me, pls?
The goal is to find biggest xor of two number, but the number must be biggest and second biggest in a range.
For example:
8 15 20 23 1 10 9
The output must be
29 (23 xor 10)
Why not 31 (8 xor 23)?
Because in range of 8 to 23, the 2 biggest number is 20 & 23, so we can only xor 20 with 23, not 8 and 23.
The program is implementation of monotonic stack (next greater element)

Answer 1

Coder Kitten , sorry i copy-paste the code without delete the comment.

Answer 2

Coder Kitten
Because if we look at the index, 8 is at index 0, and 23 is at index 3
From index 0 and 3 if i write in descending order, it would be
23
20
15
8
So, 8 xor 23 is not valid because 8 neither biggest from range (0-3) nor second biggest. But when we look at 3rd index to 5th, in descending order:
23
10
1
So if we do xor (23 and 10) is valid (both is biggest and second biggest in range (3 to 5)).
Sorry for my bad English.