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We present an efficient fixed-parameter algorithm for #SAT parameterized by the incidence treewidth, i.e., the treewidth of the bipartite graph whose vertices are the variables and clauses of the given CNF formula; a variable and a clause…

Data Structures and Algorithms · Computer Science 2007-05-23 Marko Samer , Stefan Szeider

A local search algorithm solving an NP-complete optimisation problem can be viewed as a stochastic process moving in an 'energy landscape' towards eventually finding an optimal solution. For the random 3-satisfiability problem, the…

Statistical Mechanics · Physics 2009-11-11 Sakari Seitz , Mikko Alava , Pekka Orponen

In this paper, we provide a deterministic polynomial time algorithm that determines satisfiability of 3-SAT. The complexity analysis for the algorithm takes into account no efficiency and yet provides a low enough bound, that efficient…

Data Structures and Algorithms · Computer Science 2020-07-02 Ortho Flint , Asanka Wickramasinghe , Jason Brasse , Christopher Fowler

One of the most fundamental problems in Computer Science is the Knapsack problem. Given a set of n items with different weights and values, it asks to pick the most valuable subset whose total weight is below a capacity threshold T. Despite…

Data Structures and Algorithms · Computer Science 2018-07-16 Kyriakos Axiotis , Christos Tzamos

We consider the fundamental derandomization problem of deterministically finding a satisfying assignment to a CNF formula that has many satisfying assignments. We give a deterministic algorithm which, given an $n$-variable…

Computational Complexity · Computer Science 2018-01-12 Rocco A. Servedio , Li-Yang Tan

Applying pre- and inprocessing techniques to simplify CNF formulas both before and during search can considerably improve the performance of modern SAT solvers. These algorithms mostly aim at reducing the number of clauses, literals, and…

Logic in Computer Science · Computer Science 2013-10-18 Andreas Wotzlaw , Alexander van der Grinten , Ewald Speckenmeyer

Let F be a uniformly distributed random k-SAT formula with n variables and m clauses. We prove that the Walksat algorithm from Papadimitriou (FOCS 1991)/Schoning (FOCS 1999) finds a satisfying assignment of F in polynomial time w.h.p. if…

Combinatorics · Mathematics 2017-11-17 Amin Coja-Oghlan , Alan Frieze

A pair of unit clauses is called conflicting if it is of the form $(x)$, $(\bar{x})$. A CNF formula is unit-conflict free (UCF) if it contains no pair of conflicting unit clauses. Lieberherr and Specker (J. ACM 28, 1981) showed that for…

Data Structures and Algorithms · Computer Science 2015-05-18 R. Crowston , G. Gutin , M. Jones , A. Yeo

We exhibit families of $4$-CNF formulas over $n$ variables that have sums-of-squares (SOS) proofs of unsatisfiability of degree (a.k.a. rank) $d$ but require SOS proofs of size $n^{\Omega(d)}$ for values of $d = d(n)$ from constant all the…

Computational Complexity · Computer Science 2015-04-08 Massimo Lauria , Jakob Nordström

The critical $O(N)$ CFT in spacetime dimensions $2 < d < 4$ is one of the most important examples of a conformal field theory, with the Ising CFT at $N=1$, $2 \leq d < 4$, as a notable special case. Apart from numerous physical…

High Energy Physics - Theory · Physics 2025-11-24 Johan Henriksson

We consider weighted counting of independent sets using a rational weight x: Given a graph with n vertices, count its independent sets such that each set of size k contributes x^k. This is equivalent to computation of the partition function…

Computational Complexity · Computer Science 2015-05-19 Christian Hoffmann

In this paper, we analyze the argument made by Kumar in the technical report "Necessary and Sufficient Condition for Satisfiability of a Boolean Formula in CNF and Its Implications on P versus NP problem." The paper claims to present a…

Computational Complexity · Computer Science 2021-12-14 Michael C. Chavrimootoo , Henry B. Welles

Partly on the basis of heuristic arguments from physics it has been suggested that the performance of certain types of algorithms on random $k$-SAT formulas is linked to phase transitions that affect the geometry of the set of satisfying…

Combinatorics · Mathematics 2017-11-17 Amin Coja-Oghlan , Amir Haqshenas , Samuel Hetterich

We obtain the smallest unsatisfiable formulas in subclasses of $k$-CNF (exactly $k$ distinct literals per clause) with bounded variable or literal occurrences. Smaller unsatisfiable formulas of this type translate into stronger…

Discrete Mathematics · Computer Science 2024-07-22 Tianwei Zhang , Tomáš Peitl , Stefan Szeider

We consider worst case time bounds for NP-complete problems including 3-SAT, 3-coloring, 3-edge-coloring, and 3-list-coloring. Our algorithms are based on a constraint satisfaction (CSP) formulation of these problems; 3-SAT is equivalent to…

Data Structures and Algorithms · Computer Science 2007-05-23 David Eppstein

Given a 2-SAT formula $F$ consisting of $n$ variables and $\cn$ random clauses, what is the largest number of clauses $\max F$ satisfiable by a single assignment of the variables? We bound the answer away from the trivial bounds of…

Combinatorics · Mathematics 2016-09-07 Don Coppersmith , David Gamarnik , Mohammad Hajiaghayi , Gregory B. Sorkin

In this paper, we examine the claims made by the paper "A polynomial-time algorithm for 3-SAT" by Lizhi Du. The paper claims to provide a polynomial-time algorithm for solving the NP-complete problem 3-SAT. In examining the paper's…

Computational Complexity · Computer Science 2024-04-09 Yumeng He , Matan Kotler-Berkowitz , Harry Liuson , Zeyu Nie

The exponential-time hypothesis (ETH) states that 3-SAT is not solvable in subexponential time, i.e. not solvable in O(c^n) time for arbitrary c > 1, where n denotes the number of variables. Problems like k-SAT can be viewed as special…

Computational Complexity · Computer Science 2017-06-20 Peter Jonsson , Victor Lagerkvist , Biman Roy

The standard proof of NP-Hardness of 3DM provides a power-$4$ reduction of 3SAT to 3DM. In this note, we provide a linear-time reduction. Under the exponential time hypothesis, this reduction improves the runtime lower bound from…

Computational Complexity · Computer Science 2020-03-03 Shrinu Kushagra

We investigate pseudopolynomial-time algorithms for Bounded Knapsack and Bounded Subset Sum. Recent years have seen a growing interest in settling their fine-grained complexity with respect to various parameters. For Bounded Knapsack, the…

Data Structures and Algorithms · Computer Science 2023-12-06 Lin Chen , Jiayi Lian , Yuchen Mao , Guochuan Zhang