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0votes
0answers
106views

$\mathsf{GCD}(a,b)\not\in TC^0$ while fixed dimension feasibility $ILP$ is in $TC^0$ consistent with our knowledge?

The reduction from $\mathsf{GCD}(a,b)$ is to do binary search on the feasibility of program $$r_1<au+bv<r_2$$ $$u,v\in\mathbb Z$$ where $a,b$ are given integers and we do binary search with ...
Turbo's user avatar
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2votes
1answer
140views

Do there exist two equivalent objective functions one of which can be approximated but another one cannot?

I have two equivalent problems A and B, meaning that the optimal solution of one must be the optimal solution of another one. However, it seems that problem A can be approximated but B cannot. Below ...
user avatar
3votes
1answer
377views

How hard is this combinatorial optimisation problem?

Suppose we have multiple intervals $R_1,R_2,...,R_i$ of non-negative integers. These intervals may overlap and we use $R_h(\mathrm{median})$ to denote the median integer in the $h$-th interval $R_h$, ...
user avatar
2votes
1answer
296views

Characterization of integral polyhedra

A rational polyhedron $P \subseteq \mathbb{R}^n$ is an integral polyhedron if it is the convex hull of its integer points. That is, if $P = conv(P \cap \mathbb{Z}^n)$. Equivalently, $P$ is integral if ...
Karagounis Z's user avatar
1vote
0answers
17views

Size of solutions in integer programming

Given a linear integer program $Ax\leq b$ with $A\in\mathbb Z^{m\times n}$ and $b\in\mathbb Z^m$ known is there a polynomial time algorithm to give tight upper bounds for $\log_2\|x\|_\infty$ and $\...
Turbo's user avatar
  • 13.5k
6votes
1answer
208views

Anti bin packing

I have a (practically) unlimited amount of McDonald's coupons that I can use only if I shop for at least 1 money. Thus I want to partition my family's meal into as many parts as possible that all ...
domotorp's user avatar
3votes
1answer
126views

Has Khachiyan/Porkolob's convex integer optimization been implemented?

Khachiyan and Porkolab in 'Integer optimization on convex semialgebraic sets' gave an $O(ld^{ O(k^4)})$ algorithm to minimize a degree $d$ form with integer coefficients of binary length at most $l$ ...
Turbo's user avatar
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5votes
1answer
212views

Have fixed parameter integer program algorithms ever been implemented for research use?

Have any fixed parameter integer programming algorithms described in Integer programming with a fixed number of variables been implemented? Is there a reference code that researchers can use?
Turbo's user avatar
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8votes
0answers
382views

What exactly did Lenstra prove on mixed integer linear program?

I studied Lenstra's paper https://www.jstor.org/stable/3689168. I have no clue what complexity he provides on Mixed Integer Programming (it is too terse and it is not a stand alone paper as he assumes ...
Turbo's user avatar
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7votes
1answer
142views

Quanitifier Free Presburger Arithmetic: Upper bound on solution size?

DISCLAIMER: I had originally posted this to CS.SE, but I've deleted it and moved it here, since it received little attention, and I think it is a research level question. According to this paper, if ...
Joey Eremondi's user avatar
4votes
2answers
305views

Lattice-based algorithms in practice

Are there any applications of lattice-based algorithms other than those in cryptography and integer programming? Could someone state a few papers where the primary algorithms use lattice-based LLL ...
postasaguest's user avatar
2votes
0answers
81views

General covering approximation

Consider the following integer program (general covering): $\min c \cdot x$ subject to $Ax \ge b$, where all entries in $A, b, c$ are nonnegative and $x$ is required to be nonnegative and integral. ...
Kuhndog's user avatar
2votes
1answer
155views

Can Lenstra's algorithm output all feasible solutions in O^*(f(k)) time where k is the number of variables and f is a computable function in k?

It is well-known that Lenstra's famous algorithm (presented in the paper Integer programming with a fixed number of variables) can solve an ILP problem in $O^*(f(k))$ time where k is the number of ...
Yang Yongjie's user avatar
4votes
0answers
1kviews

How to determine proper rounding in linear programming relaxations?

Recall that in the vertex cover problem we are given an undirected graph ${G=(V,E)}$ and we want to find a minimum-size set of vertices ${S}$ that “touches” all the edges of the graph, that is, such ...
IvanJ's user avatar
2votes
1answer
2kviews

Solve a simple system of linear inequalities in natural numbers

I want to find a solution to a system of linear inequalities of the following form \begin{aligned} a_1 + b &\ge a_2 \\\ \vdots \\\ a_4 + c &\ge a_1 \end{aligned} where $a_i \in \mathbb N \...
IceCube's user avatar

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