An efficient Map of elements with continuous integer keys in Java

Question

Is there a data structure that implements the Map interface and holds an array of elements with continuous integer keys efficiently in Java? In my view, to achieve best efficiency, it would be equivalent to wrapping an array or ArrayList with an index offset value in a Map interface, or a hash table with the hash function f(key) = key - offset and a minimum backing array. I know this is quite simple but I don't want to reinvent the wheels. Is there such a data structure in JDK? Or is there a library that provides an implementation? JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

If you don't need to support updates (which would make your problem a lot harder), consider passing in an IntFunction to specify the mapping instead of a Map When you have a Map, you can pass map::get, and when you don't have a map, you have a lots of easy ways to specify a mapping. For example, you can use a lambda to define a simple mapping function like: IntFunction mapper = v -> { if (v < offset || v >= offset+array.length) return null; return array[v-offset]; }