Implementation of PHP Cocktail sorting algorithm (code example)

Cocktail sort is also called bidirectional bubble sort, shaker sort, ripple sort, shuffle sort or shuttle sort. A variant of bubble sort, it is both a stable sorting algorithm and a comparison sort.

This algorithm differs from bubble sort in that it sorts in both directions each time it traverses the list. This sorting algorithm is actually more difficult to implement than bubble sort, and solves the turtle problem in bubble sort. It only provides minor performance improvements and does not improve asymptotic performance; like bubbles, while it is useful in education, it has no practical significance.

An example of cocktail sorting visualization animation is as follows:

##An example of PHP cocktail sorting code is as follows:

<?php
function cocktailSort($my_array)
{
    if (is_string($my_array))
        $my_array = str_split(preg_replace(&#39;/\s+/&#39;,&#39;&#39;,$my_array));

    do{
        $swapped = false;
        for($i=0;$i<count($my_array);$i++){
            if(isset($my_array[$i+1])){
                if($my_array[$i] > $my_array[$i+1]){
                    list($my_array[$i], $my_array[$i+1]) = array($my_array[$i+1], $my_array[$i]);
                    $swapped = true;
                }
            }
        }

        if ($swapped == false) break;

        $swapped = false;
        for($i=count($my_array)-1;$i>=0;$i--){
            if(isset($my_array[$i-1])){
                if($my_array[$i] < $my_array[$i-1]) {
                    list($my_array[$i],$my_array[$i-1]) = array($my_array[$i-1],$my_array[$i]);
                    $swapped = true;
                }
            }
        }
    }while($swapped);

    return $my_array;
}
$test_array = array(3, 0, 2, 5, -1, 4, 1);
echo "原始数组:\n";
echo implode(&#39;, &#39;,$test_array );
echo "\n排序后数组\n:";
echo implode(&#39;, &#39;,cocktailSort($test_array)). PHP_EOL;

原始数组: 3, 0, 2, 5, -1, 4, 1
排序后数组 :-1, 0, 1, 2, 3, 4, 5

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