The Seeker of Good Structure

"I visualize structures, graphs, data structures.
It seems to come easier than a lot of other things."
- Robert Tarjan

Robert E. Tarjan, born in Pomona, CA in 1948, is the generator of "good ideas", and he managed to come up with quite a few of them through his remarkable career in computer science. Interested in science and mathematics from a very early age, Tarjan was always a big fan of precise and rigorous proofs and, in high school, would often doubt his professors if they did not completely explain the reasoning behind their math. This mindset led Tarjan first to Caltech, then to Stanford which he graduated in 1972 with a PhD in computer science and a minor in mathematics. This doctoral thesis and most of his early work focused on graph-based planarity algorithms, which led Tarjan to the research and development of depth-first search algorithms and the data structures that stem from these. Tarjan's latest work was in the development of persistent data structures "in which you can keep track of previous versions as well as most recent version" of state systems and "do [so] efficiently, without copying [] entire data structure[s]" of data every time the program runs (117). Persistent data structures allow for the development of recently discovered applications in computational geometry and parallel processing called temporal databases which "are designed to recreate snapshots of the past quickly and efficiently" (118). All the numerous algorithms that Tarjan had the opportunity to work on embody his legacy while he continues his work in computer science, with some advice to present-day programmers: "What do you need to be successful? You need brains but you also need stick-to-itiveness. Many tries at a solution can fail, but then on the last try something magical happens," and that magical phenomenon is worth it - every time (119).