如何使用多维数组以及重叠检查从开始时间和结束时间获取总小时数？

Question

I have a below scenario where I need to check for the overlapping with-in a specific date array only and get total attended hours.

array (
  '2020-07-14' => 
  array (
    'total_attended_hours' => 0,
    0 => 
    array (
      'start_time' => '09:00:00',
      'end_time' => '13:00:00',
      'hours' => '4 hours 0 mins',
    ),
    1 => 
    array (
      'start_time' => '13:30:00',
      'end_time' => '16:30:00',
      'hours' => '3 hours 0 mins',
    ),
    2 => 
    array (
      'start_time' => '09:00:00',
      'end_time' => '14:00:00',
      'hours' => '5 hours 0 mins',
    ),
  ),
  '2020-07-15' => 
  array (
    'total_attended_hours' => 0,
    0 => 
    array (
      'start_time' => '13:30:00',
      'end_time' => '17:00:00',
      'hours' => '3 hours 30 mins',
    ),
    1 => 
    array (
      'start_time' => '09:00:00',
      'end_time' => '14:00:00',
      'hours' => '5 hours 0 mins',
    ),
  ),
)

As in the above example with date 2020-07-14 we have start_time and end_time :- total_attended_hours should be equals to 7 hours 30 mins``

And for next 2020-07-15 it should be total_attended_hours = 8 hours 0 mins

Playground

New issue with below array

$data = [
  '2020-07-14' => 
  [
    [
      'start_time' => '14:15:00',
      'end_time' => '17:45:00',
    ],[
      'start_time' => '14:30:00',
      'end_time' => '17:30:00',
    ],[
      'start_time' => '14:30:00',
      'end_time' => '17:30:00',
    ],
  ],
  '2020-07-15' => [
    [
      'start_time' => '13:30:00',
      'end_time' => '17:00:00',
    ],[
      'start_time' => '09:00:00',
      'end_time' => '14:00:00',
    ],
  ],
];

Result:-

Array
(
    [2020-07-14] => Array
        (
            [0] => Array
                (
                    [start_time] => 14:15:00
                    [end_time] => 17:45:00
                )

            [1] => Array
                (
                    [start_time] => 14:30:00
                    [end_time] => 17:30:00
                )

            [2] => Array
                (
                    [start_time] => 14:30:00
                    [end_time] => 17:30:00
                )

            [total_attended_hours] => 03:15:00
        )

Where as [total_attended_hours] => 03:15:00 should be [total_attended_hours] => 03:30:00

Answer 1

Here you got the algorythm:

1. For each set of Time-Bookings do the following
2. Find the smallest start_time
3. Add the duration between start_time and end_time to a sum
4. Find the next smallest Time-Booking by start_time
5. IF current_end_time < previous_end_time jump to 4 END IF
6. IF start_time < previous_end_time subtract difference from sum END IF
7. Add duration between start_time and end_time
8. Jump to 4 until there is no matching element left.

Happy coding:)

EDIT - add more clean implementation

function getSortedDays(array $days): array {
    return array_map(function (array $day) {
       array_multisort(array_column($day, 'start_time'), SORT_ASC, $day);
       
       return $day;
    }, $days);
}

function addTotalAttendedHours(array $days): array {
    $sortedDays = getSortedDays($days);
    
    $days = array_map(function (array $day) {
        $sum = (new DateTime())->setTimestamp(0);
        $previousEnd = null;
        
        foreach ($day as $time) {
            $currentStart = new DateTimeImmutable($time['start_time']);
            $currentEnd = new DateTimeImmutable($time['end_time']);

            if ($currentEnd < $previousEnd) continue; // this has been added
            
            $sum->add($currentStart->diff($currentEnd));
            
            if ($previousEnd !== null && $currentStart < $previousEnd) {
                $sum->sub($currentStart->diff($previousEnd));
            }
            
            $previousEnd = $currentEnd;
        }
        
        $attendedSeconds = $sum->getTimestamp();
        $day['total_attended_hours'] = sprintf(
            '%02u:%02u:%02u',
            $attendedSeconds / 60 / 60,
            ($attendedSeconds / 60) % 60,
            $attendedSeconds % 60
        );
        
        return $day;
    }, $sortedDays);
    
    return $days;
}

Working example .