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arXiv 1702.04679cs.CCcs.DM
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布尔满射一般值CSP的复杂性

The complexity of Boolean surjective general-valued CSPs

Peter Fulla, Hannes Uppman, Stanislav Zivny

摘要:

值约束满足问题(VCSPs)是离散优化问题,其目标函数为固定值函数之和的$(\mathbb{Q}\cup\{\infty\})$值。在布尔满射VCSP中,变量采用来自$D=\{0,1\}$的标签,并且需要最优分配来使用来自$D$的两个标签。例子包括经典的全局最小割问题和编码理论中研究的最小距离问题。我们建立了一个二分法定理,从而给出了一个完整的布尔满射VCSP的精确可解性的复杂性分类。我们的工作推广的二分法的$\{0,\infty\}$值约束语言(对应满射决策CSP)得到的Creameru和Hébrard。对于$\mathbb{Q}_{\geq 0}$ -值满射VCSP的最大化问题,我们还建立了一个关于可逼近性的二分法。与布尔满射(决策)CSP的情况不同,出现了一种新的易处理的语言类,在非满射设置中是平凡的。这个新发现的易处理类有一个有趣的数学结构,与沮丧和沮丧有关。我们的主要贡献是识别这个类,并证明它位于易处理的边界上。我们的证明的一个关键部分是一个多项式时间算法枚举所有接近最优的解决方案的广义最小割问题,这可能是独立的利益。

英文摘要:

Valued constraint satisfaction problems (VCSPs) are discrete optimisation problems with a $(\mathbb{Q}\cup\{\infty\})$-valued objective function given as a sum of fixed-arity functions. In Boolean surjective VCSPs, variables take on labels from $D=\{0,1\}$ and an optimal assignment is required to use both labels from $D$. Examples include the classical global Min-Cut problem in graphs and the Minimum Distance problem studied in coding theory. We establish a dichotomy theorem and thus give a complete complexity classification of Boolean surjective VCSPs with respect to exact solvability. Our work generalises the dichotomy for $\{0,\infty\}$-valued constraint languages (corresponding to surjective decision CSPs) obtained by Creignou and Hébrard. For the maximisation problem of $\mathbb{Q}_{\geq 0}$-valued surjective VCSPs, we also establish a dichotomy theorem with respect to approximability. Unlike in the case of Boolean surjective (decision) CSPs, there appears a novel tractable class of languages that is trivial in the non-surjective setting. This newly discovered tractable class has an interesting mathematical structure related to downsets and upsets. Our main contribution is identifying this class and proving that it lies on the borderline of tractability. A crucial part of our proof is a polynomial-time algorithm for enumerating all near-optimal solutions to a generalised Min-Cut problem, which might be of independent interest.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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