Editing Patience sorting (section)

===Algorithm for finding a longest increasing subsequence===
First, execute the sorting algorithm as described above. The number of piles is the length of a longest subsequence. Whenever a card is placed on top of a pile, put a [[back-pointer]] to the top card in the previous pile (that, by assumption, has a lower value than the new card has). In the end, follow the back-pointers from the top card in the last pile to recover a decreasing subsequence of the longest length; its reverse is an answer to the longest increasing subsequence algorithm.

S.&nbsp;Bespamyatnikh and M.&nbsp;Segal<ref name=Bespamyatnikh/> give a description of an efficient implementation of the algorithm, incurring no additional [[asymptotic]] cost over the sorting one (as the back-pointers storage, creation and traversal require linear time and space). They further show how to report ''all'' the longest increasing subsequences from the same resulting [[data structure]]s.