1. Given an array arr[] containing N integers and there are Q queries where each query consists of a range [L, R]. The task is to find whether all the elements from the given index range have even frequency or not.
   Constraints Q <= 10^5

2. Find the number of digits in the decimal representation of a/b, where a and b are two positive integers ?
   Constraints 1 <= a <= 10^16 and 1 <= b <= 10^16 ( return -1 if number of digits are infinite )

The other two questions were simple dp and sorting based which i dont remember

Can anyone provide solution for first questions, i did it with prefix xor but only half of the test cases passed.