Robert Endre Tarjan (born
April 30, 1948) is a renowned American computer scientist. He is the
discoverer of several important
graph
algorithms, including
Tarjan's
off-line least common ancestors algorithm, and co-inventor of
both
splay trees and
Fibonacci heaps.
He was
born in Pomona, California.
Education
Robert Tarjan's father was a child psychiatrist specializing in
mental retardation, and ran a state hospital. As a child, Tarjan
read a lot of science fiction, and wanted to be an
astronomer. He became interested in
mathematics after reading
Martin Gardner's mathematical games column in
Scientific American. He became
seriously interested in math in the eighth grade, thanks to a "very
stimulating" teacher.
While he was in high school, Tarjan got a job, where he worked IBM
card punch collators. He first worked with real computers at a
summer science program in 1964.
Tarjan
obtained a Bachelor's degree in
mathematics from the California Institute of
Technology in 1969. At Stanford
University, he received his Master's degree in computer science in
1971 and a Ph.D. in computer science (with a minor
in mathematics) in 1972. At Stanford, he
was supervised by
Robert Floyd and
Donald Knuth, both highly prominent
computer scientists. His Ph.D. dissertation was
An Efficient
Planarity Algorithm, and his advisor was eminent computer
scientist
Robert Floyd. Tarjan selected
computer science as his area of interest, because he believed that
CS was a way of doing mathematics that could have a practical
impact.
Computer science career
Tarjan has been teaching at Princeton University since 1985. He has
also held academic positions at Cornell University (1972-73),
University of California, Berkeley (1973-1975), Stanford University
(1974-1980), and New York University (1981-1985).
He has also been a
fellow of the NEC Research Institute (1989-1997), a Visiting
Scientist at the Massachusetts Institute of
Technology (1996).
Tarjan has vast industrial experience: he has worked at AT&T
Bell Labs (1980-1989), InterTrust Technologies (1997-2001), Compaq
(2002) and Hewlett Packard (2006-present). He has served on several
ACM and IEEE committees, and has also been editor of several
reputed journals.
Algorithms and data structures
Tarjan has designed many efficient algorithms and data structures
for solving problems in a wide variety of application areas. He has
published more than 228 refereed journal articles and book
chapters.
Tarjan is known for his pioneering work on graph theory algorithms
and data structures. Some of his well-known algorithms include the
Tarjan's
off-line least common ancestors algorithm, and the
Tarjan's
strongly connected components algorithm. The Hopcroft-Tarjan
planarity testing algorithm was
the first linear-time algorithm for planarity-testing.
Tarjan has also developed important data structures such as the
Fibonacci heap (a heap data structure
consisting of a forest of trees), and the splay tree (a
self-adjusting binary search tree; co-invented by Tarjan and
Daniel Sleator). Another significant
contribution was the analysis of the
disjoint-set data structure; he
was the first to prove the optimal runtime involving the inverse
Ackermann function.
Tarjan is currently the
James S.
McDonnell Distinguished University
Professor of Computer Science at Princeton University, and also works for Hewlett-Packard.
Awards
Tarjan received the
Turing Award
jointly with
John Hopcroft in 1986.
The citation for the award states that it was:
Tarjan was also elected an
ACM Fellow in
1994. The citation for this award
[7515] states:
Some of the other awards for Tarjan include:
Notes
References
External links