Implements "patience diff" and the patience algorithm for the longest increasing subsequence problem.

# Patience diff

diff :: Ord t => [t] -> [t] -> [Item t]Source

The difference between two lists, according to the "patience diff" algorithm.

An element of a computed difference.

# Longest increasing subsequence

longestIncreasing :: [(Int, a)] -> [(Int, a)]Source

Given: a list of distinct integers. Picks a subset of the integers in the same order, i.e. a subsequence, with the property that

- it is monotonically increasing, and
- it is at least as long as any other such subsequence.

This function uses patience sort: http://en.wikipedia.org/wiki/Patience_sorting. For implementation reasons, the actual list returned is the reverse of the subsequence.

You can pair each integer with an arbitrary annotation, which will be carried through the algorithm.