flat-tree

Map a binary tree to a list. Adapted from mafintosh/flat-tree.

Usage

```rust extern crate flat_tree;

let parent = flat_tree::parent(0); println!("parent of 0 is {}", parent); ```

You can represent a binary tree in a simple flat list using the following structure:

text 3 1 5 0 2 4 6 ...

Each number represents an index in a flat list. So a tree:

text A B C D E F G ...

would be represented as a list: [D B E A F C G]

Furthermore, indexes 0, 2, 4, 6 are on depth 0. 1, 5, 9 on depth 1. And so forth.

text depth = 2 ^ 3 depth = 1 | 1 5 depth = 0 | 0 2 4 6 ...

In some cases it is also useful to calculate an offset. Indexes 0, 1, 3, 7 have an offset 0:

text (7) (3) (1) 5 (0) 2 4 6 ...

2, 5, 11, 23 offset 1:

text 7 3 (11) 1 (5) 9 13 0 (2) 4 6 10 12 14 15

This module exposes a series of functions to help you build and maintain this data structure.