1,677 research outputs found
Prefijos y sufijos en el proyectar de la arquitectura
La relación entre la formación de las palabras y las oraciones con la de los edificio
Tree Deletion Set has a Polynomial Kernel (but no OPT^O(1) approximation)
In the Tree Deletion Set problem the input is a graph G together with an
integer k. The objective is to determine whether there exists a set S of at
most k vertices such that G-S is a tree. The problem is NP-complete and even
NP-hard to approximate within any factor of OPT^c for any constant c. In this
paper we give a O(k^4) size kernel for the Tree Deletion Set problem. To the
best of our knowledge our result is the first counterexample to the
"conventional wisdom" that kernelization algorithms automatically provide
approximation algorithms with approximation ratio close to the size of the
kernel. An appealing feature of our kernelization algorithm is a new algebraic
reduction rule that we use to handle the instances on which Tree Deletion Set
is hard to approximate
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