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This book constitutes the proceedings of the 27th International Workshop on Combinatorial Algorithms, IWOCA 2016, held in Helsinki, Finland, in August 2016.
The 35 papers presented in this volume were carefully reviewed and selected from 87 submissions. They were organized in topical sessions named: computational complexity; computational geometry; networks; enumeration; online algorithms; algorithmic graph theory; dynamic programming; combinatorial algorithms; graph algorithms; combinatorics; and probabilistics.

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Computational complexity.- On the complexity of computing the tree-breadth.-Online Chromatic Number is PSPACE-Complete.- Computational geometry.- Bounded embeddings of graphs in the plane.- Crushing Disks Efficiently.-Essential Constraints of Edge-Constrained Proximity Graphs.- Plane Bichromatic Trees of Low Degree.- Networks.- Directing Road Networks by Listing Strong Orientations.- Evangelism in Social Networks.- Distance Queries in Large-Scale Fully Dynamic Complex Networks.- Minimax Regret 1-Median Problem in Dynamic Path Networks.- Enumeration.- On Maximal Chain Subgraphs and Covers of Bipartite Graphs.- Weighted de Bruijn Graphs for the Menage Problem and Its Generalizations.- Reconfiguration of Steiner Trees in an Unweighted Graph.- Online algorithms.- Weighted Online Problems with Advice.- Finding gapped palindromes online.- Advice Complexity of the Online Search Problem.- Packed Compact Tries: A Fast and Efficient Data Structure for Online String Processing.- Algorithmic graph theory.- A boundary property for upper domination.- Upper Domination: Complexity and Approximation.- Well-quasi-ordering versus clique-width: new results on bigenic classes.- Sufficient Conditions for Tuza´s Conjecture on Packing and Covering Triangles.- Dynamic programming.- Linear Time Algorithms for Happy Vertex Coloring Problems for Trees.- Speeding up dynamic programming in the line-constrained k-median.- Combinatorial algorithms.- SOBRA - Shielding Optimization for BRAchytherapy.- A bit-scaling algorithm for integer feasibility in UTVPI constraints.- Limits of Greedy Approximation Algorithms for the Maximum Planar Subgraph Problem.- Exact Algorithms For Weighted Coloring In Special Classes of Tree and Cactus Graphs.- Graph algorithms.- Finding Cactus Roots in Polynomial Time.- Computing Giant Graph Diameters.- Faster Computation of Path-Width.- The Solution Space of Sorting with Recurring Comparison Faults.- Combinatorics.- Monotone paths in geometric triangulations.- On computing the total displacement number via weighted Motzkin paths.- Probabilistics.- Partial Covering Arrays: Algorithms and Asymptotics.- Querying Probabilistic Neighborhoods in Spatial Data Sets Efficiently.

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