Robert Tarjan

Robert Endre Tarjan (born April 30, 1948) is an American computer scientist and mathematician. He is the discoverer of several graph theory algorithms, including his strongly connected components algorithm, and co-inventor of both splay trees and Fibonacci heaps. Tarjan joined Princeton University as the James S. McDonnell Distinguished University Professor of Computer Science in 1985. He and John Hopcroft won the 1986 ACM Turing Award.

Personal life and education He was born in Pomona, California. His father, George Tarjan, raised in Hungary, was a child psychiatrist, specializing in intellectual disability, and ran a state hospital. Robert Tarjan's younger brother James became a chess grandmaster. As a child, Robert 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 with IBM punch card collators. He first worked with real computers while studying astronomy at the Summer Science Program in 1964. and Donald Knuth,

Tarjan now lives in Princeton, NJ, and Silicon Valley. He is married to Nayla Rizk. He has three daughters: Alice Tarjan, Sophie Zawacki, and Maxine Tarjan.

Computer science career Tarjan has been teaching at Princeton University since 1985.

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.

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 states:

Some of the other awards for Tarjan include: Nevanlinna Prize in Information Science (1983) Member of the American Academy of Arts and Sciences, elected 1985 National Academy of Sciences Award for Initiatives in Research (1984) Member of the National Academy of Engineering, elected 1988 Member of the American Philosophical Society, elected 1990 Paris Kanellakis Award in Theory and Practice, ACM (1999)

Selected publications

Tarjan's papers have been collectively cited over 94,000 times. Among the most cited are:

1972: Depth-first search and linear graph algorithms, R Tarjan, SIAM Journal on Computing 1 (2), 146-160 1987: Fibonacci heaps and their uses in improved network optimization algorithms, ML Fredman, RE Tarjan, Journal of the ACM (JACM) 34 (3), 596-615 1983: Data structures and network algorithms, RE Tarjan, Society for industrial and Applied Mathematics 1988: A new approach to the maximum-flow problem, V Goldberg, RE Tarjan, Journal of the ACM (JACM) 35 (4), 921-940

Patents

Tarjan holds at least 18 U.S. patents. These include:

J. Bentley, D. Sleator, and R. E. Tarjan, U. S. Patent 4,796,003, Data Compaction, 1989 N. Mishra, R. Schreiber, and R. E. Tarjan, U. S. Patent 7,818,272, Method for discovery of clusters of objects in an arbitrary undirected graph using a difference between a fraction of internal connections and maximum fraction of connections by an outside object, 2010 B. Pinkas, S. Haber, R. E. Tarjan, and T. Sander, U. S. Patent 8220036, Establishing a secure channel with a human user, 2012