Well, i don't see why this code should pass. There are simple alternatives than trying to squeeze a heavy-constant segment tree anyway, but if you still want to, you can read. I was able to pass with a Merge Sort Tree in szkopul using some constant optimization, code here. There is a simple solution using the fact that the element appears > 1/2 in the range, we can try to pick random a number between [L,R] and see if in the range, this number appears more than 1/2 times using a histogram, the probability of error is if you try k numbers