Sublinear-Time Algorithms for Computing & Embedding Gap Edit Distance
Sublinear-Time Algorithms for Computing & Embedding Gap Edit Distance
复制标题
用于计算的次线性时间算法
DOI:
10.1109/focs46700.2020.00112
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发表时间:
2020
期刊:
影响因子:
--
通讯作者:
B. Saha
中科院分区:
文献类型:
--
作者:
Tomasz Kociumaka;B. Saha
In this paper, we design new sublinear-time algorithms for solving the gap edit distance problem and for embedding edit distance to Hamming distance. For the gap edit distance problem, we give a greedy algorithm that distinguishes in time <tex>$\tilde{\mathcal{O}}(\frac{n}{k}+k^{2})$</tex> between length-n input strings with edit distance at most <tex>$k$</tex> and those with edit distance more than <tex>$4k^{2}$</tex>. This is an improvement and a simplification upon the main result of [Goldenberg, Krauthgamer, Saha, FOCS 2019], where the <tex>$k$</tex> vs <tex>$\Theta(k^{2})$</tex> gap edit distance problem is solved in <tex>$\tilde{\mathcal{O}}(\frac{n}{k}+k^{3})$</tex> time. We further generalize our result to solve the <tex>$k$</tex> vs <tex>$\alpha k$</tex> gap edit distance problem in time <tex>$\tilde{\mathcal{O}}(\frac{n}{\alpha}+k^{2}+\frac{k}{\alpha}\sqrt{nk})$</tex>, strictly improving upon the previously known bound <tex>$\tilde{\mathcal{O}}(\frac{n}{\alpha}+k^{3})$</tex>. Finally, we show that if the input strings do not have long highly periodic substrings, then the gap edit distance problem can be solved in sublinear time within any factor <tex>$\alpha > 1$</tex>. Specifically, if the strings contain no substring of length <tex>$\ell$</tex> with the shortest period of length at most <tex>$2k$</tex>, then the <tex>$k$</tex> vs <tex>$(1+\varepsilon)k$</tex> gap edit distance problem can be solved in time <tex>$\tilde{\mathcal{O}}(\frac{n}{\varepsilon^{2}k}+k^{2}\ell)$</tex>. We further give the first sublinear-time algorithm for the probabilistic embedding of edit distance to Hamming distance. Our <tex>$\tilde{\mathcal{O}}(\frac{n}{p})$</tex>-time procedure yields an embedding with distortion <tex>$k^{2}p$</tex>, where <tex>$k$</tex> is the edit distance of the original strings. Specifically, the Hamming distance of the resultant strings is between <tex>$\frac{k-p+1}{p}$</tex> and <tex>$k^{2}$</tex> with good probability. This generalizes the linear-time embedding of [Chakraborty, Goldenberg, Koucký, STOC 2016], where the resultant Hamming distance is between <tex>$k$</tex> and <tex>$k^{2}$</tex>. Our algorithm is based on a random walk over samples, which we believe will find other applications in sublinear-time algorithms.
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影响因子:
2.5
作者:
Boroujeni, Mahdi;Ehsani, Soheil;Ghodsi, Mohammad;Hajiaghayi, Mohammadtaghi;Seddighin, Saeed
通讯作者:
Seddighin, Saeed
DOI:
10.1109/focs46700.2020.00096
发表时间:
2020
期刊:
IEEE Symposium on Foundations of Computer Science
影响因子:
--
作者:
Andoni, Alexandr;Nosatzki, Negev Shekel
通讯作者:
Nosatzki, Negev Shekel
影响因子:
14.9
作者:
Delcher, AL;Kasif, S;Salzberg, SL
通讯作者:
Salzberg, SL
DOI:
10.1109/focs.2019.00029
发表时间:
2019
期刊:
IEEE Symposium on Foundations of Computer Science
影响因子:
--
作者:
Haeupler, Bernhard
通讯作者:
Haeupler, Bernhard
DOI:
--
发表时间:
2020
期刊:
STOC 2020
影响因子:
--
作者:
Goldenberg, Elazar;Rubinstein, Aviad;Saha, Barna
通讯作者:
Saha, Barna