Paths, trees, and minimum latency tours

We give improved approximation algorithms for a variety of latency minimization problems. In particular, we give a 3.59-approximation to the minimum latency problem, improving on previous algorithms by a multiplicative factor of 2. Our techniques also give similar improvements for related problems like k-traveling repairmen and its multiple depot variant. We also observe that standard techniques can be used to speed up the previous and this algorithm by a factor of O/sup /spl tilde//(n).

[1]  Sanjeev Arora,et al.  Approximation schemes for minimum latency problems , 1999, STOC '99.

[2]  Giorgio Ausiello,et al.  On Salesmen, Repairmen, Spiders, and Other Traveling Agents , 2000, CIAC.

[3]  Nikolaos V. Sahinidis,et al.  Heuristic Bounds and Test Problem Generation for the Time-Dependent Traveling Salesman Problem , 1995, Transp. Sci..

[4]  Sanjeev Arora,et al.  A 2 + ɛ approximation algorithm for the k-MST problem , 2000, SODA '00.

[5]  Teofilo F. Gonzalez,et al.  P-Complete Problems and Approximate Solutions , 1974, SWAT.

[6]  Saligrama R. Agnihothri A Mean Value Analysis of the Travelling Repairman Problem , 1988 .

[7]  David P. Williamson,et al.  Faster approximation algorithms for the minimum latency problem , 2003, SODA '03.

[8]  Santosh S. Vempala,et al.  A constant-factor approximation algorithm for the k MST problem (extended abstract) , 1996, STOC '96.

[9]  Ian R. Webb,et al.  Depth-First Solutions for the Deliveryman Problem on Tree-Like Networks: An Evaluation Using a Permutation Model , 1996, Transp. Sci..

[10]  E. Minieka The delivery man problem on a tree network , 1990 .

[11]  Abilio Lucena,et al.  Time-dependent traveling salesman problem-the deliveryman case , 1990, Networks.

[12]  Naveen Garg,et al.  A 3-approximation for the minimum tree spanning k vertices , 1996, Proceedings of 37th Conference on Foundations of Computer Science.

[13]  László Lovász,et al.  Approximating Min-sum Set Cover , 2002, APPROX.

[14]  Douglas B. West,et al.  Extremal results and algorithms for degree sequences of graphs , 1993 .

[15]  Matteo Fischetti,et al.  The Delivery Man Problem and Cumulative Matroids , 1993, Oper. Res..

[16]  Seth Pettie,et al.  The Dynamic Vertex Minimum Problem and Its Application to Clustering-Type Approximation Algorithms , 2002, SWAT.

[17]  Jon M. Kleinberg,et al.  An improved approximation ratio for the minimum latency problem , 1996, SODA '96.

[18]  Amit Kumar,et al.  Maximum Coverage Problem with Group Budget Constraints and Applications , 2004, APPROX-RANDOM.

[19]  Sanjeev Arora,et al.  A 2+epsilon approximation algorithm for the k-MST problem , 2000, SODA.

[20]  Tim Roughgarden,et al.  Approximate k-MSTs and k-Steiner trees via the primal-dual method and Lagrangean relaxation , 2001, Math. Program..

[21]  Mihalis Yannakakis,et al.  The Traveling Salesman Problem with Distances One and Two , 1993, Math. Oper. Res..

[22]  Lucio Bianco,et al.  The traveling salesman problem with cumulative costs , 1993, Networks.

[23]  Leen Stougie,et al.  On-line single-server dial-a-ride problems , 2001, Theor. Comput. Sci..

[24]  David R. Karger,et al.  Approximation algorithms for orienteering and discounted-reward TSP , 2003, 44th Annual IEEE Symposium on Foundations of Computer Science, 2003. Proceedings..

[25]  Satish Rao,et al.  The k-traveling repairman problem , 2003, SODA '03.

[26]  Mihalis Yannakakis,et al.  Searching a Fixed Graph , 1996, ICALP.

[27]  Santosh S. Vempala,et al.  A Constant-Factor Approximation Algorithm for the k-MST Problem , 1999, J. Comput. Syst. Sci..

[28]  Leen Stougie,et al.  News from the online traveling repairman , 2003, Theor. Comput. Sci..

[29]  René Sitters,et al.  The Minimum Latency Problem Is NP-Hard for Weighted Trees , 2002, IPCO.

[30]  John N. Tsitsiklis,et al.  Special cases of traveling salesman and repairman problems with time windows , 1992, Networks.

[31]  David Simchi-Levi,et al.  Minimizing the Total Flow Time of n Jobs on a Network , 1991 .

[32]  Oded Berman,et al.  Sales-delivery man problems on treelike networks , 1995, Networks.

[33]  David P. Williamson,et al.  A general approximation technique for constrained forest problems , 1992, SODA '92.

[34]  George Papageorgiou,et al.  The Complexity of the Travelling Repairman Problem , 1986, RAIRO Theor. Informatics Appl..

[35]  Bang Ye Wu,et al.  Polynomial time algorithms for some minimum latency problems , 2000, Inf. Process. Lett..

[36]  Madhu Sudan,et al.  The minimum latency problem , 1994, STOC '94.