{"title":"MATWA: A Web Toolkit for Matching under Preferences","authors":"Frederik Glitzner, David Manlove","doi":"arxiv-2409.04402","DOIUrl":"https://doi.org/arxiv-2409.04402","url":null,"abstract":"Matching markets, where agents are assigned to one another based on\u0000preferences and capacity constraints, are pervasive in various domains. This\u0000paper introduces MATWA (https://matwa.optimalmatching.com), a web application\u0000offering a rich collection of algorithms for fundamental problem models\u0000involving matching under preferences. MATWA provides results and visualizations\u0000of matching algorithm outputs based on different methods for providing problem\u0000instances. In this paper, we describe the features of the system, illustrating\u0000its usage for different problem models, and outlining the algorithm\u0000implementations that are supported. We also give evidence of usability testing\u0000and illustrate how the system was used to obtain new empirical results for a\u0000specific matching problem. MATWA is intended to be a resource for the community\u0000of researchers in the area of matching under preferences, supporting\u0000experimentation as well as aiding the understanding of matching algorithms.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Klaus Jansen, Alexandra Lassota, Malte Tutas, Adrian Vetta
{"title":"FPT Algorithms using Minimal Parameters for a Generalized Version of Maximin Shares","authors":"Klaus Jansen, Alexandra Lassota, Malte Tutas, Adrian Vetta","doi":"arxiv-2409.04225","DOIUrl":"https://doi.org/arxiv-2409.04225","url":null,"abstract":"We study the computational complexity of fairly allocating indivisible,\u0000mixed-manna items. For basic measures of fairness, this problem is hard in\u0000general. Thus, research has flourished concerning input classes where efficient\u0000algorithms exist, both for the purpose of establishing theoretical boundaries\u0000and for the purpose of designing practical algorithms for real-world instances.\u0000Notably, the paradigm of fixed-parameter tractability (FPT) has lead to new\u0000insights and improved algorithms for a variety of fair allocation problems;\u0000see, for example, Bleim et al. (IJCAI 16), Aziz et al. (AAAI 17), Bredereck et\u0000al. (EC 19) and Kulkarni et al. (EC 21). Our focus is the fairness measure maximin shares (MMS). Motivated by the\u0000general non-existence of MMS allocations, Aziz et al. (AAAI 17) studied optimal\u0000MMS allocations, namely solutions that achieve the best $alpha$-approximation\u0000for the maximin share value of every agent. These allocations are guaranteed to\u0000exist, prompting the important open question of whether optimal MMS allocations\u0000can be computed efficiently. We answer this question affirmatively by providing\u0000FPT algorithms to output optimal MMS allocations. Furthermore, our techniques\u0000extend to find allocations that optimize alternative objectives, such as\u0000minimizing the additive approximation, and maximizing some variants of global\u0000welfare. In fact, all our algorithms are designed for a more general MMS problem in\u0000machine scheduling. Here, each mixed-manna item (job) must be assigned to an\u0000agent (machine) and has a processing time and a deadline. We develop efficient\u0000algorithms running in FPT time. Formally, we present polynomial time algorithms\u0000w.r.t. the input size times some function dependent on the parameters that\u0000yield optimal maximin-value approximations (among others) when parameterized by\u0000a set of natural parameters","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RCM++:Reverse Cuthill-McKee ordering with Bi-Criteria Node Finder","authors":"JiaJun Hou, HongJie Liu, ShengXin Zhu","doi":"arxiv-2409.04171","DOIUrl":"https://doi.org/arxiv-2409.04171","url":null,"abstract":"The Reverse Cuthill-McKee (RCM) algorithm is a graph-based method for\u0000reordering sparse matrices, renowned for its effectiveness in minimizing matrix\u0000bandwidth and profile. This reordering enhances the efficiency of matrix\u0000operations, making RCM pivotal among reordering algorithms. In the context of\u0000executing the RCM algorithm, it is often necessary to select a starting node\u0000from the graph representation of the matrix. This selection allows the\u0000execution of BFS (Breadth-First Search) to construct the level structure. The\u0000choice of this starting node significantly impacts the algorithm's performance,\u0000necessitating a heuristic approach to identify an optimal starting node,\u0000commonly referred to as the RCM starting node problem. Techniques such as the\u0000minimum degree method and George-Liu (GL) algorithm are popular solutions. This paper introduces a novel algorithm addressing the RCM starting node\u0000problem by considering both the eccentricity and the width of the node during\u0000the run. Integrating this algorithm with the RCM algorithm, we introduce RCM++.\u0000Experimental results demonstrate that RCM++ outperforms existing RCM methods in\u0000major software libraries, achieving higher quality results with comparable\u0000computation time. This advancement fosters the further application and\u0000development of the RCM algorithm.The code related to this research has been\u0000made available at https://github.com/SStan1/RCM_PP.git.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Klaus Jansen, Kai Kahler, Lis Pirotton, Malte Tutas
{"title":"Improving the Parameter Dependency for High-Multiplicity Scheduling on Uniform Machines","authors":"Klaus Jansen, Kai Kahler, Lis Pirotton, Malte Tutas","doi":"arxiv-2409.04212","DOIUrl":"https://doi.org/arxiv-2409.04212","url":null,"abstract":"We address scheduling problems on uniform machines with high-multiplicity\u0000encoding, introducing a divide and conquer approach to assess the feasibility\u0000of a general Load Balancing Problem (LBP). Via reductions, our algorithm can\u0000also solve the more well-known problems $Q|C_{max}$ (makespan minimization),\u0000$Q|C_{min}$ (santa claus) and $Q|C_{text{envy}}$ (envy minimization).\u0000State-of-the-art algorithms for these problems, e.g. by Knop et al. (Math.\u0000Program. '23), have running times with parameter dependency\u0000$p_{max}^{O(d^2)}$, where $p_{max}$ is the largest processing time and $d$ is\u0000the number of different processing times. We partially answer the question\u0000asked by Kouteck'y and Zink (ISAAC'20) about whether this quadratic dependency\u0000of $d$ can be improved to a linear one: Under the natural assumption that the\u0000machines are similar in a way that $s_{max}/s_{min} leq p_{max}^{O(1)}$ and\u0000$tauleq p_{max}^{O(1)}$, our proposed algorithm achieves parameter\u0000dependency $p_{max}^{O(d)}$ for the problems\u0000${Q|{C_{max},C_{min},C_{text{envy}}}}$. Here, $tau$ is the number of\u0000distinct machine speeds. Even without this assumption, our running times\u0000achieve a state-of-the-art parameter dependency and do so with an entirely\u0000different approach.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Constant Approximating Disjoint Paths on Acyclic Digraphs is W[1]-hard","authors":"Michał Włodarczyk","doi":"arxiv-2409.03596","DOIUrl":"https://doi.org/arxiv-2409.03596","url":null,"abstract":"In the Disjoint Paths problem, one is given a graph with a set of $k$ vertex\u0000pairs $(s_i,t_i)$ and the task is to connect each $s_i$ to $t_i$ with a path,\u0000so that the $k$ paths are pairwise disjoint. In the optimization variant, Max\u0000Disjoint Paths, the goal is to maximize the number of vertex pairs to be\u0000connected. We study this problem on acyclic directed graphs, where Disjoint\u0000Paths is known to be W[1]-hard when parameterized by $k$. We show that in this\u0000setting Max Disjoint Paths is W[1]-hard to $c$-approximate for any constant\u0000$c$. To the best of our knowledge, this is the first non-trivial result\u0000regarding the parameterized approximation for Max Disjoint Paths with respect\u0000to the natural parameter $k$. Our proof is based on an elementary\u0000self-reduction that is guided by a certain combinatorial object constructed by\u0000the probabilistic method.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fine-Grained Equivalence for Problems Related to Integer Linear Programming","authors":"Lars Rohwedder, Karol Węgrzycki","doi":"arxiv-2409.03675","DOIUrl":"https://doi.org/arxiv-2409.03675","url":null,"abstract":"Integer Linear Programming with $n$ binary variables and $m$ many\u0000$0/1$-constraints can be solved in time $2^{tilde O(m^2)} text{poly}(n)$ and\u0000it is open whether the dependence on $m$ is optimal. Several seemingly\u0000unrelated problems, which include variants of Closest String, Discrepancy\u0000Minimization, Set Cover, and Set Packing, can be modelled as Integer Linear\u0000Programming with $0/1$ constraints to obtain algorithms with the same running\u0000time for a natural parameter $m$ in each of the problems. Our main result\u0000establishes through fine-grained reductions that these problems are equivalent,\u0000meaning that a $2^{O(m^{2-varepsilon})} text{poly}(n)$ algorithm with\u0000$varepsilon > 0$ for one of them implies such an algorithm for all of them. In the setting above, one can alternatively obtain an $n^{O(m)}$ time\u0000algorithm for Integer Linear Programming using a straightforward dynamic\u0000programming approach, which can be more efficient if $n$ is relatively small\u0000(e.g., subexponential in $m$). We show that this can be improved to\u0000${n'}^{O(m)} + O(nm)$, where $n'$ is the number of distinct (i.e.,\u0000non-symmetric) variables. This dominates both of the aforementioned running\u0000times.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fast ($sim N$) Diffusion Map Algorithm","authors":"Julio Candanedo","doi":"arxiv-2409.05901","DOIUrl":"https://doi.org/arxiv-2409.05901","url":null,"abstract":"In this work we explore parsimonious manifold learning techniques,\u0000specifically for Diffusion-maps. We demonstrate an algorithm and it's\u0000implementation with computational complexity (in both time and memory) of $sim\u0000N$, with $N$ representing the number-of-samples. These techniques are essential\u0000for large-scale unsupervised learning tasks without any prior assumptions, due\u0000to sampling theorem limitations.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"106 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Does Subset Sum Admit Short Proofs?","authors":"Michał Włodarczyk","doi":"arxiv-2409.03526","DOIUrl":"https://doi.org/arxiv-2409.03526","url":null,"abstract":"We investigate the question whether Subset Sum can be solved by a\u0000polynomial-time algorithm with access to a certificate of length poly(k) where\u0000k is the maximal number of bits in an input number. In other words, can it be\u0000solved using only few nondeterministic bits? This question has motivated us to initiate a systematic study of\u0000certification complexity of parameterized problems. Apart from Subset Sum, we\u0000examine problems related to integer linear programming, scheduling, and group\u0000theory. We reveal an equivalence class of problems sharing the same hardness\u0000with respect to having a polynomial certificate. These include Subset Sum and\u0000Boolean Linear Programming parameterized by the number of constraints.\u0000Secondly, we present new techniques for establishing lower bounds in this\u0000regime. In particular, we show that Subset Sum in permutation groups is at\u0000least as hard for nondeterministic computation as 3Coloring in\u0000bounded-pathwidth graphs.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Space-Efficient Algorithm for Integer Programming with Few Constraints","authors":"Lars Rohwedder, Karol Węgrzycki","doi":"arxiv-2409.03681","DOIUrl":"https://doi.org/arxiv-2409.03681","url":null,"abstract":"Integer linear programs $min{c^T x : A x = b, x in mathbb{Z}^n_{ge\u00000}}$, where $A in mathbb{Z}^{m times n}$, $b in mathbb{Z}^m$, and $c in\u0000mathbb{Z}^n$, can be solved in pseudopolynomial time for any fixed number of\u0000constraints $m = O(1)$. More precisely, in time $(mDelta)^{O(m)}\u0000text{poly}(I)$, where $Delta$ is the maximum absolute value of an entry in\u0000$A$ and $I$ the input size. Known algorithms rely heavily on dynamic programming, which leads to a space\u0000complexity of similar order of magnitude as the running time. In this paper, we\u0000present a polynomial space algorithm that solves integer linear programs in\u0000$(mDelta)^{O(m (log m + loglogDelta))} text{poly}(I)$ time, that is, in\u0000almost the same time as previous dynamic programming algorithms.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Online Scheduling via Gradient Descent for Weighted Flow Time Minimization","authors":"Qingyun Chen, Sungjin Im, Aditya Petety","doi":"arxiv-2409.03020","DOIUrl":"https://doi.org/arxiv-2409.03020","url":null,"abstract":"In this paper, we explore how a natural generalization of Shortest Remaining\u0000Processing Time (SRPT) can be a powerful emph{meta-algorithm} for online\u0000scheduling. The meta-algorithm processes jobs to maximally reduce the objective\u0000of the corresponding offline scheduling problem of the remaining jobs:\u0000minimizing the total weighted completion time of them (the residual optimum).\u0000We show that it achieves scalability for minimizing total weighted flow time\u0000when the residual optimum exhibits emph{supermodularity}. Scalability here\u0000means it is $O(1)$-competitive with an arbitrarily small speed augmentation\u0000advantage over the adversary, representing the best possible outcome achievable\u0000for various scheduling problems. Thanks to this finding, our approach does not require the residual optimum to\u0000have a closed mathematical form. Consequently, we can obtain the schedule by\u0000solving a linear program, which makes our approach readily applicable to a rich\u0000body of applications. Furthermore, by establishing a novel connection to\u0000emph{substitute valuations in Walrasian markets}, we show how to achieve\u0000supermodularity, thereby obtaining scalable algorithms for various scheduling\u0000problems, such as matroid scheduling, generalized network flow, and generalized\u0000arbitrary speed-up curves, etc., and this is the emph{first} non-trivial or\u0000scalable algorithm for many of them.","PeriodicalId":501525,"journal":{"name":"arXiv - CS - Data Structures and Algorithms","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}