CPM’s 20th Anniversary: A Statistical Retrospective -- Quasi-distinct Parsing and Optimal Compression Methods -- Generalized Substring Compression -- Text Indexing, Suffix Sorting, and Data Compression: Common Problems and Techniques -- Contracted Suffix Trees: A Simple and Dynamic Text Indexing Data Structure -- Linear Time Suffix Array Construction Using D-Critical Substrings -- On the Value of Multiple Read/Write Streams for Data Compression -- Reoptimization of the Shortest Common Superstring Problem -- LCS Approximation via Embedding into Local Non-repetitive Strings -- An Efficient Matching Algorithm for Encoded DNA Sequences and Binary Strings -- Fast Searching in Packed Strings -- New Complexity Bounds for Image Matching under Rotation and Scaling -- Online Approximate Matching with Non-local Distances -- Faster and Space-Optimal Edit Distance “1” Dictionary -- Approximate Matching for Run-Length Encoded Strings Is 3sum-Hard -- Modeling and Algorithmic Challenges in Online Social Networks -- Permuted Longest-Common-Prefix Array -- Periodic String Comparison -- Deconstructing Intractability: A Case Study for Interval Constrained Coloring -- Maximum Motif Problem in Vertex-Colored Graphs -- Fast RNA Structure Alignment for Crossing Input Structures -- Sparse RNA Folding: Time and Space Efficient Algorithms -- Multiple Alignment of Biological Networks: A Flexible Approach -- Graph Mining: Patterns, Generators and Tools -- Level-k Phylogenetic Networks Are Constructable from a Dense Triplet Set in Polynomial Time -- The Structure of Level-k Phylogenetic Networks -- Finding All Sorting Tandem Duplication Random Loss Operations -- Average-Case Analysis of Perfect Sorting by Reversals -- Statistical Properties of Factor Oracles -- Haplotype Inference Constrained by Plausible Haplotype Data -- Efficient Inference of Haplotypes from Genotypes on a Pedigree with Mutations and Missing Alleles (Extented Abstract).

This book constitutes the refereed proceedings of the 20th Annual Symposium on Combinatorial Pattern Matching, CPM 2009, held in Lille, France in June 2009. The 27 revised full papers presented together with 3 invited talks were carefully reviewed and selected from 63 submissions. The papers address all areas related to combinatorial pattern matching and its applications, such as coding and data compression, computational biology, data mining, information retrieval, natural language processing, pattern recognition, string algorithms, string processing in databases, symbolic computing and text searching.