Communication, Dynamics and Renormalization -- Fast and Powerful Hashing using Tabulation -- Green Barrier Coverage with Mobile Sensors -- A Refined Complexity Analysis of Finding the Most Vital Edges for Undirected Shortest Paths -- Orthogonal Graph Drawing with Inflexible Edges -- Linear time Constructions of some d-Restriction Problems -- Efficiently Testing T-Interval Connectivity in Dynamic Graphs -- Competitive Strategies for Online Clique Clustering -- Scheduling with Gaps: New Models and Algorithms -- MinMax-Distance Gathering on given Meeting Points -- Evacuating Robots from a Disk Using Face-to-Face Communication -- Planarity of Streamed Graphs -- Clique-width of Graph Classes Defined by Two Forbidden Induced Subgraphs -- Randomized Adaptive Test Cover -- Contraction Blockers for Graphs with Forbidden Induced Paths -- Label Placement in Road Maps -- Discrete Stochastic Submodular Maximization: Adaptive vs. Non-Adaptive vs. Offline -- Parameterized Algorithms and Kernels for 3-Hitting Set with Parity Constraints -- Simple strategies versus optimal schedules in multi-agent patrolling -- Sharing Non-Anonymous Costs of Multiple Resources Optimally -- Algorithms solving the Matching Cut problem -- End-Vertices of Graph Search Algorithms -- Deciding the On-line Chromatic Number of a Graph with Pre-coloring is PSPACE-complete -- A Lex-BFS-based recognition algorithm for Robinsonian matrices -- Mixed Map Labeling -- Optimal Online Edge Coloring of Planar Graphs with Advice -- Approximability of Two Variants of Multiple Knapsack -- Block Sorting is Hard -- An opportunistic text indexing structure based on run length encoding -- PSPACE-completeness of Bloxorz and of Games with 2-Buttons -- Advice Complexity of Fine-Grained Job Shop Scheduling.

This book constitutes the refereed conference proceedings of the 9th International Conference on Algorithms and Complexity, CIAC 2015, held in Paris, France, in May 2015. The 30 revised full papers presented were carefully reviewed and selected from 93 submissions and are presented together with 2 invited papers. The papers present original research in the theory and applications of algorithms and computational complexity.