TY - JOUR

T1 - Increasing the minimum degree of a graph by contractions

AU - Golovach, Petr A.

AU - Kamiński, Marcin

AU - Paulusma, Daniël

AU - Thilikos, Dimitrios M.

PY - 2013/4/15

Y1 - 2013/4/15

N2 - The Degree Contractibility problem is to test whether a given graph G can be modified to a graph of minimum degree at least d by using at most k contractions. We prove the following three results. First, Degree Contractibility is NP-complete even when d=14. Second, it is fixed-parameter tractable when parameterized by k and d. Third, it is W[1]-hard when parameterized by k. We also study its variant where the input graph is weighted, i.e., has some edge weighting and the contractions preserve these weights. The Weighted Degree Contractibility problem is to test if a weighted graph G can be contracted to a weighted graph of minimum weighted degree at least d by using at most k weighted contractions. We show that this problem is NP-complete and that it is fixed-parameter tractable when parameterized by k. In addition, we pinpoint a relationship with the problem of finding a minimal edge-cut of maximum size in a graph and study the parameterized complexity of this problem and its variants.

AB - The Degree Contractibility problem is to test whether a given graph G can be modified to a graph of minimum degree at least d by using at most k contractions. We prove the following three results. First, Degree Contractibility is NP-complete even when d=14. Second, it is fixed-parameter tractable when parameterized by k and d. Third, it is W[1]-hard when parameterized by k. We also study its variant where the input graph is weighted, i.e., has some edge weighting and the contractions preserve these weights. The Weighted Degree Contractibility problem is to test if a weighted graph G can be contracted to a weighted graph of minimum weighted degree at least d by using at most k weighted contractions. We show that this problem is NP-complete and that it is fixed-parameter tractable when parameterized by k. In addition, we pinpoint a relationship with the problem of finding a minimal edge-cut of maximum size in a graph and study the parameterized complexity of this problem and its variants.

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U2 - 10.1016/j.tcs.2013.02.030

DO - 10.1016/j.tcs.2013.02.030

M3 - Article

AN - SCOPUS:84875829263

SN - 0304-3975

VL - 481

SP - 74

EP - 84

JO - Theoretical Computer Science

JF - Theoretical Computer Science

ER -