when we are passing arrays in any functions , we don’t have to use pointers, as arrays are already by reference, but why bhaiya is using (*arr) in function call?
Inversion count doubt
hi @CODER_JATIN its just a way of specifying that its a pointer.
you can write it like int arr[] or int *arr, arr stores the address of the first element of the array so both the notations are fine
okay okay , thank you 
and as this(inversion_sort) problem is the implementation of merge_sort, So, how do we approach a new problem related to a particular algorithm!!
@CODER_JATIN you’ll learn that from experience! Once you have solved a wide range of problems you will start getting intution yourself as to how to approach a particular problem and what algorithm is best suited for it.
okay okay. Thank you