Matroid Algorithms Under Size-Sensitive Independence Oracles
- URL: http://arxiv.org/abs/2605.00201v1
- Date: Thu, 30 Apr 2026 20:26:35 GMT
- Title: Matroid Algorithms Under Size-Sensitive Independence Oracles
- Abstract summary: Matroid algorithms assume that each independence query can be answered in constant time, regardless of the size of the queried set.<n>In particular, for natural and widely studied classes such as graphic matroids, even a single independence query can require work linear in the size of the set.<n>We introduce a size-sensitive cost model where the cost of a query $Q$ scales with $|Q|$.
- Score: 19.61677355524952
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: The standard oracle model for matroid algorithms assumes that each independence query can be answered in constant time, regardless of the size of the queried set. While this abstraction has underpinned much of the theoretical progress in matroid optimization, it masks the true computational effort required by these algorithms. In particular, for natural and widely studied classes such as graphic matroids, even a single independence query can require work linear in the size of the set, making the constant-time assumption implausible. We address this gap by introducing a size-sensitive cost model where the cost of a query $Q$ scales with $|Q|$. Nearly linear-time oracle implementations exist for broad families of matroids, and this refined abstraction therefore captures the true cost of query evaluation while allowing for a more faithful comparison between general matroids and their natural special cases. Within this framework we study three fundamental algorithmic tasks: finding a basis of a matroid, approximating its rank, and approximating its partition size. We establish tight results, proving nearly matching upper and lower bounds that show the optimal query cost is (up to logarithmic factors) quadratic in the size of the matroid. On the algorithmic side, our upper bounds are realized by explicit procedures that construct the desired solution. On the complexity side, our lower bounds are unconditional and already hold even for weaker distinguishing formulations of the problems. Finally, for matroids with maximum circuit size at most $c$, we show that the quadratic barrier can be broken, providing an algorithm that calculates the maximum-weight basis with expected query cost $\mathcal{O}(n^{2-1/c} \log n)$.
Related papers
- Provably Adaptive Linear Approximation for the Shapley Value and Beyond [73.0940890296463]
A fundamental and long-standing challenge is their efficient approximation.<n>We develop a linear-space algorithm that requires $P(|hatboldsymbol-boldsymbol|_2geq)leq $ for all commonly used semi-values.<n>Our algorithm allows explicit minimization of the mean square error for each specific utility function.
arXiv Detail & Related papers (2026-04-09T16:38:14Z) - Fast and Accurate Homomorphic Softmax Evaluation [2.5766624796160777]
Homomorphic encryption is one of the main solutions for building secure and privacy-preserving solutions for Machine Learning as a Service.
We focus on the Softmax function, defined by $mathrmSM(mathbfx) = left(exp(x_i) / sum_j=1n exp(x_j) right)_1le ile n$.
arXiv Detail & Related papers (2024-10-15T02:01:36Z) - Sum-of-Squares inspired Quantum Metaheuristic for Polynomial Optimization with the Hadamard Test and Approximate Amplitude Constraints [76.53316706600717]
Recently proposed quantum algorithm arXiv:2206.14999 is based on semidefinite programming (SDP)
We generalize the SDP-inspired quantum algorithm to sum-of-squares.
Our results show that our algorithm is suitable for large problems and approximate the best known classicals.
arXiv Detail & Related papers (2024-08-14T19:04:13Z) - Discretely Beyond $1/e$: Guided Combinatorial Algorithms for Submodular Maximization [13.86054078646307]
For constrained, not necessarily monotone submodular, all known approximation algorithms with ratio greater than $1/e$ require continuous ideas.<n>For algorithms, the best known approximation ratios for both size and matroid constraint are obtained by a simple randomized greedy algorithm.
arXiv Detail & Related papers (2024-05-08T16:39:59Z) - Accelerating Matroid Optimization through Fast Imprecise Oracles [40.94053997358159]
We analyze practical algorithms which only use few clean queries w.r.t. the quality of the dirty oracle.
Notably, we prove that our algorithms are, in many respects, best-possible.
We outline extensions to other matroid oracle types, non-free dirty oracles and other matroid problems.
arXiv Detail & Related papers (2024-02-05T07:14:18Z) - Linear Query Approximation Algorithms for Non-monotone Submodular
Maximization under Knapsack Constraint [16.02833173359407]
This work introduces two constant factor approximation algorithms with linear query complexity for non-monotone submodular over a ground set of size $n$ subject to a knapsack constraint.
$mathsfDLA$ is a deterministic algorithm that provides an approximation factor of $6+epsilon$ while $mathsfRLA$ is a randomized algorithm with an approximation factor of $4+epsilon$.
arXiv Detail & Related papers (2023-05-17T15:27:33Z) - Pseudonorm Approachability and Applications to Regret Minimization [73.54127663296906]
We convert high-dimensional $ell_infty$-approachability problems to low-dimensional pseudonorm approachability problems.
We develop an algorithmic theory of pseudonorm approachability, analogous to previous work on approachability for $ell$ and other norms.
arXiv Detail & Related papers (2023-02-03T03:19:14Z) - Minimax Optimization with Smooth Algorithmic Adversaries [59.47122537182611]
We propose a new algorithm for the min-player against smooth algorithms deployed by an adversary.
Our algorithm is guaranteed to make monotonic progress having no limit cycles, and to find an appropriate number of gradient ascents.
arXiv Detail & Related papers (2021-06-02T22:03:36Z) - Near-Optimal Regret Bounds for Contextual Combinatorial Semi-Bandits
with Linear Payoff Functions [53.77572276969548]
We show that the C$2$UCB algorithm has the optimal regret bound $tildeO(dsqrtkT + dk)$ for the partition matroid constraints.
For general constraints, we propose an algorithm that modifies the reward estimates of arms in the C$2$UCB algorithm.
arXiv Detail & Related papers (2021-01-20T04:29:18Z) - Online Model Selection for Reinforcement Learning with Function
Approximation [50.008542459050155]
We present a meta-algorithm that adapts to the optimal complexity with $tildeO(L5/6 T2/3)$ regret.
We also show that the meta-algorithm automatically admits significantly improved instance-dependent regret bounds.
arXiv Detail & Related papers (2020-11-19T10:00:54Z) - Quick Streaming Algorithms for Maximization of Monotone Submodular
Functions in Linear Time [16.346069386394703]
We consider the problem of monotone, submodular over a ground set of size $n$ subject to cardinality constraint $k$.
We introduce the first deterministic algorithms with linear time complexity; these algorithms are streaming algorithms.
Our single-pass algorithm obtains a constant ratio in $lceil n / c rceil + c$ oracle queries, for any $c ge 1$.
arXiv Detail & Related papers (2020-09-10T16:35:54Z) - Maximizing Determinants under Matroid Constraints [69.25768526213689]
We study the problem of finding a basis $S$ of $M$ such that $det(sum_i in Sv_i v_i v_itop)$ is maximized.
This problem appears in a diverse set of areas such as experimental design, fair allocation of goods, network design, and machine learning.
arXiv Detail & Related papers (2020-04-16T19:16:38Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.