Before revision:  In this paper , we present a new compressed index on RLBWT, which we call r-index-f, in which r-index is improved for faster locatequeries. in constant time with O(r) words of space, which is a bit step forward in computation time from the previous best result of O(\log \log n) time for string length n and O(r) words of space.
After revision:  In this paper , we present a new compressed index on RLBWT, which we call r-index-f in constant time with O(r) words of space, which is a bit step forward in computation time from the previous best result of O(\log \log n) time for string length n and O(r) words of space.