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# NAME

Algorithm::TimelinePacking - Arrange time intervals into non-overlapping lines

## Example Output

The module arranges overlapping time intervals into non-overlapping rows,
perfect for Gantt-style visualizations:

![Hadoop jobs timeline](images/hadoop-jobs-example.png)

*75 Hadoop MapReduce jobs arranged into 11 parallel execution lanes.
See `examples/hadoop-jobs.html` for the full demo.*

# SYNOPSIS

    use Algorithm::TimelinePacking;

    my $packer = Algorithm::TimelinePacking->new(
        space => 5,      # minimum gap between intervals on same line
        width => 1000,   # optional: scale output to fit this width
    );

    # Each slice: [start, end, ...metadata]
    my @slices = (
        [1000, 1200, 'job1', 'alice'],
        [1100, 1300, 'job2', 'bob'],    # overlaps with job1
        [1500, 1600, 'job3', 'carol'],
    );

    my ($lines, $latest) = $packer->arrange_slices(\@slices);

    # $lines is an arrayref of arrayrefs, each containing non-overlapping slices
    # $latest is the normalized end timestamp

# DESCRIPTION

Algorithm::TimelinePacking solves the interval graph coloring problem: given a
set of potentially overlapping time intervals, it assigns them to the minimum
number of "lines" (rows) such that no two intervals on the same line overlap.

Originally developed to visualize Hadoop MapReduce job execution timelines,
the algorithm is completely generic and works for any Gantt-style visualization:
conference schedules, meeting room allocation, project timelines, TV programming,
resource booking systems, or any scenario with overlapping time ranges.

The algorithm uses a greedy first-fit approach, placing each interval on the
first available line where it fits without overlap.

# EXAMPLES

## Conference Schedule

Arrange talks into rooms so no two talks overlap in the same room:

    use Algorithm::TimelinePacking;

    my $packer = Algorithm::TimelinePacking->new(space => 15);  # 15 min between talks

    # Talks: [start_minutes, end_minutes, title, speaker, track]
    my @talks = (
        [540,  600, 'Opening Keynote',       'Margot Tenenbaum', 'keynote'],
        [600,  645, 'GopherScript for Beginners', 'Kevin McCallister', 'beginner'],
        [600,  645, 'Advanced Burrow Patterns',   'Ferris Mueller', 'advanced'],
        [600,  690, 'Workshop: Testing',     'Beatrix Bourbon', 'workshop'],
        [660,  705, 'Database Wrangling',    'Chester Copperpot', 'beginner'],
        [660,  705, 'Unsafe Memory Access',  'Wanda Maximoff', 'advanced'],
        [720,  780, 'Lunch',                 '',        'break'],
        [780,  825, 'Async/Await Deep Dive', 'Inigo Montoya', 'advanced'],
        [780,  870, 'Workshop: Web Apps',    'Rufus Firefly', 'workshop'],
        [840,  900, 'Closing Panel',         'Various', 'keynote'],
    );

    my ($rooms, $end) = $packer->arrange_slices(\@talks);

    for my $i (0 .. $#$rooms) {
        print "Room ", $i + 1, ":\n";
        for my $talk (@{$rooms->[$i]}) {
            printf "  %02d:%02d - %s (%s)\n",
                int($talk->[0] / 60), $talk->[0] % 60,
                $talk->[2], $talk->[3];
        }
    }

    # Output shows minimum rooms needed, with no scheduling conflicts

## Hadoop Job Timeline

The original use case - visualize MapReduce job execution:

    my @jobs = (
        [$start_epoch, $end_epoch, $job_id, $user, $map_tasks, $reduce_tasks],
        ...
    );

    my ($lines, $latest) = $packer->arrange_slices(\@jobs);
    # Feed $lines to D3.js or other visualization library

# ATTRIBUTES

## space

    my $packer = Algorithm::TimelinePacking->new(space => 10);