What .NET dictionary supports a “find nearest key” operation?

Question

I\'m converting some C++ code to C# and it calls std::map::lower_bound(k) to find an entry in the map whose key is equal to or greater than k. However, I don\'t see any way

Answer 1

The problem is that a dictionary/hash table is designed to arrive at a unique memory location based on an input value, so you'll need a data structure that is designed to accommodate a range related to each value you store, and at the same time update each interval correctly

I think skip lists (or balanced binary trees) can help you. Although they cannot perform lookups in O(n), they can do logarithmically and still faster than trees.

I know this is not a proper answer since I cannot say that the .NET BCL already contains such a class, you'll unfortunately have to implement one yourself, or find a 3rd party assembly that supports it for you. There seems to be a nice example over at The CodeProject here, though.