Philippe Flajolet (; 1 December 1948 – 22 March 2011) was a French

computer scientist A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus (al ...

Biography

A former student of

École Polytechnique École may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * École, Savoi ...

, Philippe Flajolet received his PhD in computer science from

University Paris Diderot Paris Diderot University, also known as Paris 7 (french: Université Paris Diderot), was a French university located in Paris, France. It was one of the inheritors of the historic University of Paris, which was split into 13 universities in 197 ...

in 1973 and state doctorate from

Paris-Sud 11 University Paris-Sud University (French: ''Université Paris-Sud''), also known as University of Paris — XI (or as Université d'Orsay before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, in ...

in 1979. Most of Philippe Flajolet's research work was dedicated towards general methods for analyzing the

computational complexity In computer science, the computational complexity or simply complexity of an algorithm is the amount of resources required to run it. Particular focus is given to computation time (generally measured by the number of needed elementary operations) ...

algorithm In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...

s, including the theory of

average-case complexity In computational complexity theory, the average-case complexity of an algorithm is the amount of some computational resource (typically time) used by the algorithm, averaged over all possible inputs. It is frequently contrasted with worst-case comp ...

. He introduced the theory of

analytic combinatorics In combinatorics, the symbolic method is a technique for counting combinatorial objects. It uses the internal structure of the objects to derive formulas for their generating functions. The method is mostly associated with Philippe Flajolet and ...

. With Robert Sedgewick of

Princeton University Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...

, he wrote the first book-length treatment of the topic, the 2009 book entitled ''

Analytic Combinatorics In combinatorics, the symbolic method is a technique for counting combinatorial objects. It uses the internal structure of the objects to derive formulas for their generating functions. The method is mostly associated with Philippe Flajolet and ...

''. In 1993, together with Rainer Kemp, Helmut Prodinger and Robert Sedgewick, Flajolet initiated the successful series of workshops and conferences which was key to the development of a research community around the analysis of algorithms, and which evolved into the AofA—International Meeting on Combinatorial, Probabilistic, and Asymptotic Methods in the Analysis of Algorithms. A summary of his research up to 1998 can be found in the articl
"Philippe Flajolet's research in Combinatorics and Analysis of Algorithms"
by H. Prodinger and W. Szpankowski, ''Algorithmica'' 22 (1998), 366–387. At the time of his death from a serious illness, Philippe Flajolet was a research director (senior research scientist) at

INRIA The National Institute for Research in Digital Science and Technology (Inria) () is a French national research institution focusing on computer science and applied mathematics. It was created under the name ''Institut de recherche en informatiq ...

in Rocquencourt. From 1994 to 2003 he was a corresponding member of the

French Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...

, and was a full member from 2003 on. He was also a member of the

Academia Europaea The Academia Europaea is a pan-European Academy of Humanities, Letters, Law, and Sciences. The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europea ...

Memory

The

HyperLogLog HyperLogLog is an algorithm for the count-distinct problem, approximating the number of distinct elements in a multiset. Calculating the ''exact'' cardinality of the distinct elements of a multiset requires an amount of memory proportional to t ...

commands of

Redis Redis (; Remote Dictionary Server) is an in-memory data structure store, used as a distributed, in-memory key–value database, cache and message broker, with optional durability. Redis supports different kinds of abstract data structures, su ...

, released in April 2014, are prefixed with "PF" in honor of Philippe Flajolet. The

Flajolet Lecture Prize The Philippe Flajolet Lecture Prize is awarded to for contributions to analytic combinatorics and analysis of algorithms, in the fields of theoretical computer science. This prize is named in memory of Philippe Flajolet. History The Flajolet Le ...

, which has been awarded since 2014, was also named in honor of him.

Selected works

* with Robert Sedgewick
''An Introduction to the Analysis of Algorithms''
2nd edition, Addison-Wesley, Boston, Mass. 1995, * with Robert Sedgewick: ''

''. Cambridge University Press, Cambridge 2009, * ''Random tree models in the analysis of algorithms''. INRIA, Rocquencourt 1987 (Rapports de recherche; Vol. 729) * with

Andrew Odlyzko Andrew Michael Odlyzko (Andrzej Odłyżko) (born 23 July 1949) is a Polish-American mathematician and a former head of the University of Minnesota's Digital Technology Center and of the Minnesota Supercomputing Institute. He began his career in ...

: ''Singularity analysis of generating functions''. University Press, Stanford, Calif. 1988

References

External links

Philippe Flajolet's Home Page

* Luc Devroye, ttp://luc.devroye.org/flajolet-1948-2011/ Philippe Flajolet, 1 December 1948 – 22 March 2011
Philippe Flajolet
Philippe Flajolet,

On-Line Encyclopedia of Integer Sequences The On-Line Encyclopedia of Integer Sequences (OEIS) is an online database of integer sequences. It was created and maintained by Neil Sloane while researching at AT&T Labs. He transferred the intellectual property and hosting of the OEIS to the ...

{{DEFAULTSORT:Flajolet, Philippe 1948 births 2011 deaths École Polytechnique alumni French computer scientists Members of the French Academy of Sciences Members of Academia Europaea 20th-century French mathematicians 21st-century French mathematicians Graph theorists Number theorists