Approximate Maintenance of Maximum Subarray Sum in the Sliding Window Model

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Suzuki, Ryo, Yamaguchi, Yutaro
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866914507508416512
author Suzuki, Ryo
Yamaguchi, Yutaro
author_facet Suzuki, Ryo
Yamaguchi, Yutaro
contents In the sliding window model, we are required to maintain the target statistics over the most recent $n$ elements of a data stream, which is captured by a window of size $n$ sliding over the data stream. Exact computation usually requires space linear in $n$, and the central goal is approximate maintenance using sublinear space. In this paper, we study the problem of maintaining the maximum subarray sum in the sliding window model. While the classical Kadane's algorithm computes the exact answer using constant space in the static setting, it does not extend directly, because a new element makes the oldest one expire, which may invalidate the optimal subarray so far. Our first observation is that the so-called Smooth Histogram framework can lead to a constant-factor approximation (in the sense of relative error) using $O((\log n)^2)$ bits of space. We then refine this framework accordingly, which enables for any $ε> 0$ to maintain a $(1 \pm ε)$-approximation using $O(ε^{-1}(\log n)^2)$ bits of space and $O(ε^{-1}\log n)$ operations per update. The space complexity is asymptotically optimal.
format Preprint
id arxiv_https___arxiv_org_abs_2604_23168
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Approximate Maintenance of Maximum Subarray Sum in the Sliding Window Model
Suzuki, Ryo
Yamaguchi, Yutaro
Data Structures and Algorithms
In the sliding window model, we are required to maintain the target statistics over the most recent $n$ elements of a data stream, which is captured by a window of size $n$ sliding over the data stream. Exact computation usually requires space linear in $n$, and the central goal is approximate maintenance using sublinear space. In this paper, we study the problem of maintaining the maximum subarray sum in the sliding window model. While the classical Kadane's algorithm computes the exact answer using constant space in the static setting, it does not extend directly, because a new element makes the oldest one expire, which may invalidate the optimal subarray so far. Our first observation is that the so-called Smooth Histogram framework can lead to a constant-factor approximation (in the sense of relative error) using $O((\log n)^2)$ bits of space. We then refine this framework accordingly, which enables for any $ε> 0$ to maintain a $(1 \pm ε)$-approximation using $O(ε^{-1}(\log n)^2)$ bits of space and $O(ε^{-1}\log n)$ operations per update. The space complexity is asymptotically optimal.
title Approximate Maintenance of Maximum Subarray Sum in the Sliding Window Model
topic Data Structures and Algorithms
url https://arxiv.org/abs/2604.23168