Data structure for fast query and update of cumulative sums.

Fenwick trees are a O(log N) data structure for updating cumulative sums. This implementation comes with an operation to find a least element for which real-valued cumulative sum reaches certain value, and allows for storage of arbitrary information in the nodes.

FenwickTree

Fenwick trees are a O(log N) data structure for updating cumulative sums. This implementation comes with an operation to find a least element for which real-valued cumulative sum reaches certain value, and allows for storage of arbitrary information in the nodes.

See description on Wikipedia.

Official releases are on Hackage.

This package is also a part of Stackage - a stable subset of Hackage.