Cocktail Shaker Sort – sorting in a shaker, a variant of bidirectional bubble sort.
The algorithm works like this:
- Select the starting direction of the iteration in the loop (usually left-to-right)
- Next, the numbers are checked in pairs
- If the next element is larger, they are swapped
- At the end, the iteration process restarts with the direction reversed
- Iterates until there are no more permutations
The time complexity of the algorithm is similar to the bubble one – O(n2) .
An example implementation in PHP:
#!/usr/bin/env php
<?php
function cocktailShakeSort($numbers)
{
echo implode(",", $numbers),"\n";
$direction = false;
$sorted = false;
do {
$direction = !$direction;
$firstIndex = $direction == true ? 0 : count($numbers) - 1;
$lastIndex = $direction == true ? count($numbers) - 1 : 0;
$sorted = true;
for(
$i = $firstIndex;
$direction == true ? $i < $lastIndex : $i > $lastIndex;
$direction == true ? $i++ : $i--
) {
$lhsIndex = $direction ? $i : $i - 1;
$rhsIndex = $direction ? $i + 1 : $i;
$lhs = $numbers[$lhsIndex];
$rhs = $numbers[$rhsIndex];
if ($lhs > $rhs) {
$numbers[$lhsIndex] = $rhs;
$numbers[$rhsIndex] = $lhs;
$sorted = false;
}
}
} while ($sorted == false);
echo implode(",", $numbers);
}
$numbers = [2, 1, 4, 3, 69, 35, 55, 7, 7, 2, 6, 203, 9];
cocktailShakeSort($numbers);
?>Links
Sources
https://www.youtube.com/watch?v=njClLBoEbfI
https://www.geeksforgeeks.org/cocktail-sort/< br />
https://rosettacode.org/wiki/Sorting_algorithms/Cocktail_sort
