https://github.com/mikolalysenko/segment-tree

Basic segment tree data structure
https://github.com/mikolalysenko/segment-tree

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Basic segment tree data structure

• Host: GitHub
• URL: https://github.com/mikolalysenko/segment-tree
• Owner: mikolalysenko
• License: mit
• Created: 2013-06-11T19:18:01.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-07-18T01:32:44.000Z (over 11 years ago)
• Last Synced: 2024-10-20T14:27:55.017Z (2 months ago)
• Language: JavaScript
• Size: 129 KB
• Stars: 14
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
segment-tree

============

A minimal implementation of a segment tree for storing run-length encoded arrays with updates.

## Example

```javascript

var tree = require("segment-tree").zeros(10)

tree.set(1, 1)

tree.set(2, 1)

console.log(tree.length)

console.log(tree.pointers)

console.log(tree.values)

```

## Install

    npm install segment-tree

## API

```javascript

var SegmentTree = require("segment-tree")

```

### `SegmentTree(length, pointers, values)`

SegmentTree constructor

* `length` is the size of the segment tree

* `pointers` is a sorted list of pointers

* `values` is a sorted list of values

The segment tree object has the same properties as the arguments.

### `SegmentTree.proto.get(index)`

Retrieves the value `index`

* `index` is the coordinate of the value to retrieve

**Returns** The value at `index`

### `SegmentTree.proto.set(index, v)`

Sets the value at `index` to `v`

* `index` is the index to update

* `v` is the new value

**Returns** `v`

### `SegmentTree.proto.slice(begin[, end])`

Returns a slice of the segment tree.  Same semantics as [Array.slice](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice)

* `begin` is the start of the interval

* `end` is the end of the interval

**Returns** A 1-level deep slice of the segment tree

### `SegmentTree.proto.toArray([array])`

Unpacks the segment tree into an array

* `array` gets the output.  If not specified a new array is allocated

**Returns** `array`

### `SegmentTree.zeros(size)`

Create an empty segment tree

* `size` is the size of the new segment tree

**Returns** A new segment tree

### `SegmentTree.fromArray(array)`

Encodes an array into a segment tree

* `array` is the array to encode

**Returns** A new segment tree encoding `array`

### `SegmentTree.fromGenericArray(array)`

Encodes an array into a segment tree, except instead of using [] to access the array it uses .get()

* `array` is the array to encode

**Returns** A new segment tree encoding `array`

## Credits

(c) 2013 Mikola Lysenko. MIT License