Alberto Marchetti-Spaccamela – författare

This book constitutes the refereed proceedings of the 5th Workshop on Algorithm Engineering, WAE 2001, held in Aarhus, Denmark, in August 2001. The 15 revised full papers presented were carefully reviewed and selected from 25 submissions. Among the topics addressed are implementation, experimental testing, and fine-tuning of discrete algorithms; novel use of discrete algorithms in other disciplines; empirical research on algorithms and data structures; and methodological issues regarding the process of converting user requirements into efficient algorithmic solutions and implemenations.

This book constitutes the refereed proceedings of the 5th Workshop on Algorithm Engineering, WAE 2001, held in Aarhus, Denmark, in August 2001. The 15 revised full papers presented were carefully reviewed and selected from 25 submissions. Among the topics addressed are implementation, experimental testing, and fine-tuning of discrete algorithms; novel use of discrete algorithms in other disciplines; empirical research on algorithms and data structures; and methodological issues regarding the process of converting user requirements into efficient algorithmic solutions and implemenations.

This book constitutes the carefully refereed post-proceedings of the 22nd International Workshop on Graph-Theoretic Concepts in Computer Science, WG '96, held in Cadenabbia, Italy, in June 1996.The 30 revised full papers presented in the volume were selected from a total of 65 submissions. This collection documents the state of the art in the area. Among the topics addressed are graph algorithms, graph rewriting, hypergraphs, graph drawing, networking, approximation and optimization, trees, graph computation, and others.

This book constitutes the refereed proceedings of the 24th International Colloquium on Automata, Languages and Programming, ICALP '97, held in Bologna, Italy, in July 1997. ICALP '97 celebrated the 25th anniversary of the European Association for Theoretical Computer Science (EATCS), which has sponsored the ICALP meetings since 1972.The volume presents 73 revised full papers selected from a total of 197 submissions. Also included are six invited contributions. ICALP is one of the few flagship conferences in the area. The book addresses all current topics in theoretical computer science.

N COMPUTER applications we are used to live with approximation. Var­ I ious notions of approximation appear, in fact, in many circumstances. One notable example is the type of approximation that arises in numer­ ical analysis or in computational geometry from the fact that we cannot perform computations with arbitrary precision and we have to truncate the representation of real numbers. In other cases, we use to approximate com­ plex mathematical objects by simpler ones: for example, we sometimes represent non-linear functions by means of piecewise linear ones. The need to solve difficult optimization problems is another reason that forces us to deal with approximation. In particular, when a problem is computationally hard (i. e. , the only way we know to solve it is by making use of an algorithm that runs in exponential time), it may be practically unfeasible to try to compute the exact solution, because it might require months or years of machine time, even with the help of powerful parallel computers. In such cases, we may decide to restrict ourselves to compute a solution that, though not being an optimal one, nevertheless is close to the optimum and may be determined in polynomial time. We call this type of solution an approximate solution and the corresponding algorithm a polynomial-time approximation algorithm. Most combinatorial optimization problems of great practical relevance are, indeed, computationally intractable in the above sense. In formal terms, they are classified as Np-hard optimization problems.

ICALP 2009, the 36th edition of the International Colloquium on Automata, Languages and Programming, was held on the island of Rhodes, July 6-10, 2009. ICALP is a series of annual conferences of the European Association for Theoretical Computer Science (EATCS) which ?rst took place in 1972. This year, the ICALP program consisted of the established track A (focusing on algorithms, complexity and games) and track B (focusing on logic, automata, semantics and theory of programming), and of the recently introduced track C (in 2009 focusing on foundations of networked computation). In response to the call for papers, the Program Committee received 370 s- missions: 223 for track A, 84 for track B and 63 for track C. Out of these, 108 papers were selected for inclusion in the scienti?c program: 62 papers for track A, 24 for track B and 22 for track C. The selection was made by the Program Committees based on originality, quality, and relevance to theoretical computer science. The quality of the manuscripts was very high indeed, and many dese- ing papers could not be selected. ICALP 2009 consisted of ?ve invited lectures and the contributed papers.Thisvolumeoftheproceedingscontainsallcontributedpaperspresentedintrack AtogetherwiththepapersbytheinvitedspeakersKurtMehlhorn(Max-Planck- Institut fu ..r Informatik, Saarbru ..cken)and Christos Papadimitriou(University of California at Berkeley). A companion volume contains all contributed papers presented at the conference in track B and track C, together with the papers by the invited speakers Georg Gottlob (University of Oxford), Tom Henzinger ' (EcolePolytechniqueF' ed' eraledeLausanne),andNoamNisan(Google,TelAviv, and Hebrew University).

ICALP 2009, the 36th edition of the International Colloquium on Automata, Languages and Programming, was held on the island of Rhodes, July 6–10, 2009. ICALP is a series of annual conferences of the European Association for Theoretical Computer Science (EATCS) which ?rst took place in 1972. This year, the ICALP program consisted of the established track A (focusing on algorithms, complexity and games) and track B (focusing on logic, automata, semantics and theory of programming), and of the recently introduced track C (in 2009 focusing on foundations of networked computation). In response to the call for papers, the Program Committee received 370 s- missions: 223 for track A, 84 for track B and 63 for track C. Out of these, 108 papers were selected for inclusion in the scienti?c program: 62 papers for track A, 24 for track B and 22 for track C. The selection was made by the Program Committees based on originality, quality, and relevance to theoretical computer science. The quality of the manuscripts was very high indeed, and many dese- ing papers could not be selected. ICALP 2009 consisted of ?ve invited lectures and the contributed papers.

ICALP 2009, the 36th edition of the International Colloquium on Automata, Languages and Programming, was held on the island of Rhodes, July 6–10, 2009. ICALP is a series of annual conferences of the European Association for Theoretical Computer Science (EATCS) which ?rst took place in 1972. This year, the ICALP program consisted of the established track A (focusing on algorithms, complexity and games) and track B (focusing on logic, automata, semantics and theory of programming), and of the recently introduced track C (in 2009 focusing on foundations of networked computation). In response to the call for papers, the Program Committee received 370 s- missions: 223 for track A, 84 for track B and 63 for track C. Out of these, 108 papers were selected for inclusion in the scienti?c program: 62 papers for track A, 24 for track B and 22 for track C. The selection was made by the Program Committees based on originality, quality, and relevance to theoretical computer science. The quality of the manuscripts was very high indeed, and many dese- ing papers could not be selected. ICALP 2009 consisted of ?ve invited lectures and the contributed papers.

This book constitutes the refereed proceedings of the First International ICST Conference on Theory and Practice of Algorithms in (Computer) Systems, TAPAS 2011, held in Rome, Italy, in April 2011. The 25 papers presented, including three short papers by invited speakers, were carefully reviewed and selected from 45 submissions. The papers all feature original research in the design, implementation and evaluation of algorithms with special focus on algorithms for combinatorial optimization problems, and to real-world applications, engineering and experimental analysis of algorithms - thus fostering the cooperation among researchers in computer science, networking, discrete mathematics, mathematical programming and operations research.

This book constitutes the refereed proceedings of the First International ICST Conference on Theory and Practice of Algorithms in (Computer) Systems, TAPAS 2011, held in Rome, Italy, in April 2011. The 25 papers presented, including three short papers by invited speakers, were carefully reviewed and selected from 45 submissions. The papers all feature original research in the design, implementation and evaluation of algorithms with special focus on algorithms for combinatorial optimization problems, and to real-world applications, engineering and experimental analysis of algorithms - thus fostering the cooperation among researchers in computer science, networking, discrete mathematics, mathematical programming and operations research.

This book constitutes the refereed proceedings of the 12th International Symposium on Experimental Algorithms, SEA 2013, held in Rome, Italy, in June 2013. The 32 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 73 submissions. The papers are organized in topical sections on transportation networks and graph algorithms, combinatorics and enumeration, data structures and compression, network partitioning and bioinformatics, mathematical programming, geometry and optimization, and scheduling and local search.

This book constitutes the refereed proceedings of the 12th International Symposium on Experimental Algorithms, SEA 2013, held in Rome, Italy, in June 2013. The 32 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 73 submissions. The papers are organized in topical sections on transportation networks and graph algorithms, combinatorics and enumeration, data structures and compression, network partitioning and bioinformatics, mathematical programming, geometry and optimization, and scheduling and local search.

N COMPUTER applications we are used to live with approximation. Var­ I ious notions of approximation appear, in fact, in many circumstances. One notable example is the type of approximation that arises in numer­ ical analysis or in computational geometry from the fact that we cannot perform computations with arbitrary precision and we have to truncate the representation of real numbers. In other cases, we use to approximate com­ plex mathematical objects by simpler ones: for example, we sometimes represent non-linear functions by means of piecewise linear ones. The need to solve difficult optimization problems is another reason that forces us to deal with approximation. In particular, when a problem is computationally hard (i. e. , the only way we know to solve it is by making use of an algorithm that runs in exponential time), it may be practically unfeasible to try to compute the exact solution, because it might require months or years of machine time, even with the help of powerful parallel computers. In such cases, we may decide to restrict ourselves to compute a solution that, though not being an optimal one, nevertheless is close to the optimum and may be determined in polynomial time. We call this type of solution an approximate solution and the corresponding algorithm a polynomial-time approximation algorithm. Most combinatorial optimization problems of great practical relevance are, indeed, computationally intractable in the above sense. In formal terms, they are classified as Np-hard optimization problems.