A greedy interval packer

Given a list of intervals the packer will return a list of partitions with no overlapping intervals.

Intervals are just objects with integer properties for start and end where start < end.

Usage

expect(intervalPacker([
    { start: 2, end: 4, value: '4' },
    { start: 4, end: 6, value: '5' },
    { start: 3, end: 4, value: '7' },
    { start: 3, end: 5, value: '6' },
    { start: 1, end: 3, value: '2' },
    { start: 3, end: 5, value: '3' },
    { start: 0, end: 2, value: '0' },
    { start: 4, end: 5, value: '8' },
    { start: 2, end: 6, value: '1' }
]), 'to equal', [
    [{ start: 0, end: 2, value: '0' }, { start: 2, end: 6, value: '1' }],
    [{ start: 1, end: 3, value: '2' }, { start: 3, end: 5, value: '3' }],
    [{ start: 2, end: 4, value: '4' }, { start: 4, end: 6, value: '5' }],
    [{ start: 3, end: 5, value: '6' }],
    [{ start: 3, end: 4, value: '7' }, { start: 4, end: 5, value: '8' }]
]);

If you specify the partitions to be grouped, you will get the following result:

expect(intervalPacker([
    { start: 2, end: 4, value: '4' },
    { start: 4, end: 6, value: '5' },
    { start: 3, end: 4, value: '7' },
    { start: 3, end: 5, value: '6' },
    { start: 1, end: 3, value: '2' },
    { start: 3, end: 5, value: '3' },
    { start: 0, end: 2, value: '0' },
    { start: 4, end: 5, value: '8' },
    { start: 2, end: 6, value: '1' }
], { groupPartitions: true }), 'to equal', [
    [
        [{ start: 0, end: 2, value: '0' }]
    ],
    [
        [{ start: 3, end: 6, value: '1' }],
        [{ start: 3, end: 5, value: '3' }]
    ],
    [
        [{ start: 6, end: 10, value: '2' }],
        [{ start: 6, end: 8, value: '4' }]
    ]
]);

Installation

Node

Install it with NPM or add it to your package.json:

$ npm install greedy-interval-packer

Then:

var intervalPacker = require('greedy-interval-packer');

expect(intervalPacker([
    { start: 0, end: 2, value: '0' },
    { start: 3, end: 6, value: '1' },
    { start: 6, end: 10, value: '2' },
    { start: 3, end: 5, value: '3' },
    { start: 6, end: 8, value: '4' }
]), 'to equal', [
    [
        { start: 0, end: 2, value: '0' },
        { start: 3, end: 6, value: '1' },
        { start: 6, end: 10, value: '2' }
    ],
    [
        { start: 3, end: 5, value: '3' },
        { start: 6, end: 8, value: '4' }
    ]
]);

        expect(intervalPacker([
            { start: 0, end: 2, value: '0' }, { start: 3, end: 6, value: '1' }, { start: 6, end: 10, value: '2' },
            { start: 3, end: 5, value: '3' }, { start: 6, end: 8, value: '4' }
        ], { groupPartitions: true }), 'to equal', [
            [
                [{ start: 0, end: 2, value: '0' }]
            ],
            [
                [{ start: 3, end: 6, value: '1' }],
                [{ start: 3, end: 5, value: '3' }]
            ],
            [
                [{ start: 6, end: 10, value: '2' }],
                [{ start: 6, end: 8, value: '4' }]
            ]
        ]);

Browser

Include greedy-interval-packer.js.

<script src="greedy-interval-packer.js"></script>

this will expose the greedyIntervalPacker function under the following namespace:

var intervalPacker = com.one.greedyIntervalPacker;

expect(intervalPacker([
    { start: 0, end: 2, value: '0' },
    { start: 3, end: 6, value: '1' },
    { start: 6, end: 10, value: '2' },
    { start: 3, end: 5, value: '3' },
    { start: 6, end: 8, value: '4' }
]), 'to equal', [
    [
        { start: 0, end: 2, value: '0' },
        { start: 3, end: 6, value: '1' },
        { start: 6, end: 10, value: '2' }
    ],
    [
        { start: 3, end: 5, value: '3' },
        { start: 6, end: 8, value: '4' }
    ]
]);

RequireJS

Include the library with RequireJS the following way:

require.config({
    paths: {
        greedyIntervalPacker: 'path/to/greedy-interval-packer'
    }
});

define(['greedyIntervalPacker'], function (intervalPacker) {
    expect(intervalPacker([
        { start: 0, end: 2, value: '0' },
        { start: 3, end: 6, value: '1' },
        { start: 6, end: 10, value: '2' },
        { start: 3, end: 5, value: '3' },
        { start: 6, end: 8, value: '4' }
    ]), 'to equal', [
        [
            { start: 0, end: 2, value: '0' },
            { start: 3, end: 6, value: '1' },
            { start: 6, end: 10, value: '2' }
        ],
        [
            { start: 3, end: 5, value: '3' },
            { start: 6, end: 8, value: '4' }
        ]
    ]);
});

License

Copyright © 2015, One.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.