PHP Searching and Sorting Algorithm: Bogo sort

Last update on May 30 2022 11:42:27 (UTC/GMT +8 hours)

PHP Searching and Sorting Algorithm: Exercise-14 with Solution

Write a PHP program to sort a list of elements using Bogo sort.

In computer science, bogosort is a particularly ineffective sorting algorithm based on the generate and test paradigm. The algorithm successively generates permutations of its input until it finds one that is sorted. It is not useful for sorting but may be used for educational purposes, to contrast it with other more realistic algorithms.

Sample Solution :

PHP Code :

<?php
function issorted($list)
{
    $cnt = count($list);
    for($j = 1; $j < $cnt; $j++)
    {
        if($list[$j-1] > $list[$j])
		{
                return false;
        }
    }
    return true;
}
function bogo_sort($list)
{
    do
    {
        shuffle($list);
    }
    while(!issorted($list));
    return $list;
}
$test_array = array(100, 0, 2, 5, -1, 4, 1);
echo "\nOriginal Array :\n";
echo implode(', ',$test_array );
echo "\nSorted Array :\n";
echo implode(', ',bogo_sort($test_array)). PHP_EOL;
?>

Sample Output:

Original Array :                                                    
100, 0, 2, 5, -1, 4, 1                                              
Sorted Array :                                                      
-1, 0, 1, 2, 4, 5, 100

Flowchart :

PHP Code Editor:

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Previous: Write a PHP program to sort a list of elements using Bead sort.
Next: Write a PHP program to sort a list of elements using Strand sort.

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PHP: Tips of the Day

How to Sort Multi-dimensional Array by Value?

Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

Example:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

And finally with PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual

Ref : https://bit.ly/3i77vCC