Editing Robert Tarjan (section)

===Algorithms and data structures===
Tarjan is known for his pioneering work on graph theory algorithms and data structures. Some of his well-known algorithms include [[Tarjan's off-line least common ancestors algorithm]], [[Tarjan's strongly connected components algorithm]], and [[Bridge (graph theory)#Tarjan's bridge-finding algorithm|Tarjan's bridge-finding algorithm]], and he was one of five co-authors of the [[median of medians]] linear-time [[selection algorithm]]. The Hopcroft–Tarjan [[planarity testing]] algorithm was the first linear-time algorithm for planarity testing.<ref>{{cite book
 | last = Kocay
 | first = William
 |author2=Kreher, Donald L
  | title = Graphs, algorithms, and optimization
 | url = https://archive.org/details/graphsalgorithms00will
 | url-access = limited
 | publisher = Chapman & Hall/CRC
 | location = Boca Raton
 | year = 2005
 | isbn = 978-1-58488-396-8
 | oclc = 56319851
 | chapter = Planar Graphs
 | page = [https://archive.org/details/graphsalgorithms00will/page/n196 312]
}}</ref>

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]].<ref name="Tarjan1984">{{cite journal |first1=Robert E. |last1=Tarjan |author1-link=Robert E. Tarjan |first2=Jan |last2=van Leeuwen |author2-link=Jan van Leeuwen |title=Worst-case analysis of set union algorithms |journal=[[Journal of the ACM]] |volume=31 |issue=2 |pages=245–281 |year=1984 |doi= 10.1145/62.2160|s2cid=5363073 |doi-access=free }}</ref>