TY - CHAP
T1 - Faster Algorithms for 1-Mappability of a Sequence
AU - Alzamel, Mai
AU - Charalampopoulos, Panagiotis
AU - Iliopoulos, Costas
AU - Pissis, Solon
AU - Radoszewski, Jakub
AU - Sung, Wing Kin
PY - 2017/11/16
Y1 - 2017/11/16
N2 - In the k-mappability problem, we are given a string x of length n and integers m and k, and we are asked to count, for each length-m factor y of x, the number of other factors of length m of x that are at Hamming distance at most k from y. We focus here on the version of the problem where k= 1. The fastest known algorithm for k= 1 requires time O(mnlog n/ log log n) and space O(n). We present two new algorithms that require worst-case time O(mn) and O(nlog nlog log n), respectively, and space O(n), thus greatly improving the state of the art. Moreover, we present another algorithm that requires average-case time and space O(n) for integer alphabets of size σ if m = Ω(log σn). Notably, we show that this algorithm is generalizable for arbitrary k, requiring average-case time O(kn) and space O(n) if m = Ω(k logσn).
AB - In the k-mappability problem, we are given a string x of length n and integers m and k, and we are asked to count, for each length-m factor y of x, the number of other factors of length m of x that are at Hamming distance at most k from y. We focus here on the version of the problem where k= 1. The fastest known algorithm for k= 1 requires time O(mnlog n/ log log n) and space O(n). We present two new algorithms that require worst-case time O(mn) and O(nlog nlog log n), respectively, and space O(n), thus greatly improving the state of the art. Moreover, we present another algorithm that requires average-case time and space O(n) for integer alphabets of size σ if m = Ω(log σn). Notably, we show that this algorithm is generalizable for arbitrary k, requiring average-case time O(kn) and space O(n) if m = Ω(k logσn).
UR - http://www.scopus.com/inward/record.url?scp=85038216754&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-71147-8_8
DO - 10.1007/978-3-319-71147-8_8
M3 - Other chapter contribution
AN - SCOPUS:85038216754
SN - 9783319711461
VL - 10628 LNCS
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 109
EP - 121
BT - Combinatorial Optimization and Applications - 11th International Conference, COCOA 2017, Proceedings
PB - Springer Verlag
T2 - 11th International Conference on Combinatorial Optimization and Applications, COCOA 2017
Y2 - 16 December 2017 through 18 December 2017
ER -