Data structure for permutations in Java

Question

I need to store a permutation of n integers and be able to compute both the permutation of a value and the inverse operation in efficient time.

I.e, I need to store a reordering of values [0...n-1] in such a way I can ask for position(i) and value(j) (with 0 <= i,j <= n).

With an example—Suppose we have the following permutation of values:

I need the following operations:

I know libraries in C++ for that, such as: https://github.com/fclaude/libcds2

Is there any structure or library in Java that allows to do that and is efficient in space and time?

Are there any guarantees about duplicates? – Sync Nov 08 '17 at 14:17 — Sync, Nov 08 '17 at 14:17

score 1 · Answer 1 · answered Nov 08 '17 at 14:22

1

If there are no duplicates, the List interface will suit your needs.

It provides the following methods:

answered Nov 08 '17 at 14:22

Sync

1 Answers1