Philippe Flajolet

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Philippe Flajolet
Philippe Flajolet, in 2006, at the Analysis of Algorithms international conference
Born (1948-12-01)1 December 1948
Died 22 March 2011(2011-03-22) (aged 62)
Nationality French
Fields Mathematics, Computer Science
Institutions INRIA
University of Paris
Alma mater Paris-Sud 11 University
University Paris Diderot
Doctoral advisor Maurice Nivat
Jean Vuillemin
Doctoral students Claude Puech
Jean-Marc Steyaert
Paul Zimmermann
Notable awards Knight of the Légion d'honneur
CNRS Silver Medal
Doctor honoris causa from Université libre de Bruxelles

Philippe Flajolet (French: [flaʒɔlɛ]; 1 December 1948 – 22 March 2011[1]) was a French computer scientist.


A former student of École Polytechnique, Philippe Flajolet received his Ph.D. in computer science from University Paris Diderot in 1973 and state doctorate from Paris-Sud 11 University in 1979. Most of Philippe Flajolet's research work was dedicated towards general methods for analyzing the computational complexity of algorithms, including the theory of average-case complexity.[2] He introduced the theory of analytic combinatorics. With Robert Sedgewick of Princeton University, he wrote the first book-length treatment of the topic, the 2009 book entitled Analytic Combinatorics.

A summary of his research up to 1998 can be found in the article "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 in Rocquencourt.

In his last book, An Introduction to the Analysis of Algorithms (2nd Edition, 2012), whose co-author is Robert Sedgewick, writes an eulogy

"Sadly, I am writing from a distant part of the world to pay my respects to my longtime friend and colleague, Philippe Flajolet. I am very sorry not to be there in person, but I know that there will be many opportunities to honor Philippe in the future and expect to be fully and personally involved on these occasions.

Brilliant, creative, inquisitive, and indefatigable, yet generous and charming, Philippe’s approach to life was contagious. He changed many lives, including my own. As our research papers led to a survey paper, then to a monograph, then to a book, then to two books, then to a life’s work, I learned, as many students and collaborators around the world have learned, that working with Philippe was based on a genuine and heartfelt camaraderie. We met and worked together in cafes, bars, lunchrooms, and lounges all around the world. Philippe’s routine was always the same. We would discuss something amusing that happened to one friend or another and then get to work. After a wink, a hearty but quick laugh, a puff of smoke, another sip of a beer, a few bites of steak frites, and a drawn out “Well...” we could proceed to solve the problem or prove the theorem. For so many of us, these moments are frozen in time.

The world has lost a brilliant and productive mathematician. Philippe’s untimely passing means that many things may never be known. But his legacy is a coterie of followers passionately devoted to Philippe and his mathematics who will carry on. Our conferences will include a toast to him, our research will build upon his work, our papers will include the inscription “Dedicated to the memory of Philippe Flajolet ,” and we will teach generations to come. Dear friend, we miss you so very much, but rest assured that your spirit will live on in our work."

From 1994 to 2003 he was a corresponding member of the French Academy of Sciences, and was a full member from 2003 on. He was also a member of the Academia Europaea.


The HyperLogLog commands of Redis, released in April 2014, are prefixed with "PF" in honor of Philippe Flajolet.[3]

Selected works[edit]


  1. ^ "Philippe Flajolet : Algorithmix nous a quittés !" [Philippe Flajolet : Algorithmix has departed this world !]. INRIA Alumni (in French). 23 March 2011. 
  2. ^ Philippe Flajolet and J.S. Vitter. Average-case analysis of algorithms and data structures. Technical report, Institut National de Recherche en Informatique et en Automatique, August 1987.
  3. ^ Salvatore Sanfilippo (April 1, 2014). "Redis new data structure: the HyperLogLog". Antirez weblog. Archived from the original on 2014-08-02. 

External links[edit]