CODEWITHSUNDEEP
php
shayne
shayne

Reputation: 87

Bubble sort array, how can I make this php bubble sort code better or more effective?

how can I make this php bubble sort code better or more effective? 

// bubble sort for $AR 
for($i = count($AR)-1 ; $i <= 1; $i--) 
   for($j = 0; $j < $i; $j++) {
      if($AR[$j] > $AR[$j+1]) {
          $t = $AR[$j];
          $AR[$j] = $AR[$j+1];
          $AR[$j+1] = $t;
       } //if
   } //for j

Upvotes: 1

Views: 723

Answers (3)

Asur
Asur

Reputation: 4017

Algorithms are algorithms, if you make some modifications and achieve a better performance you won't be using the Bubble sorting algorithm anymore, because it would have changed.

If you want a increase performance you need to change the algorithm, Quick Sort is generally considered to be the best sorting one. As an example of the implementation in php: 

// QuickSort Algorithm function
function quickSort(array $array) {
    if (count($array) == 0) {
        return $array;
    }
    $pivot = $array[0];
    $left = $right = array();
    for($i = 1; $i < count($array); $i ++) {
        if ($array[$i] < $pivot) {
            $left[] = $array[$i];
        } else {
            $right[] = $array[$i];
        }
    }
    return array_merge(quickSort($left), array(
            $pivot
    ), quickSort($right));
}

Of course, it always depends on the situation, if you optimize it you would be basing your code on that algorithm but not making bubble algorithm better or more effective.

Check this post, where is really well documented almost every type of sorting in php.

Hope this helps you!

Upvotes: 4

GertG
GertG

Reputation: 979

As it stands, your code won't do anything at all. You got the first loop condition wrong. With that corrected, it looks like a perfectly fine bubble sort.

// bubble sort for $AR 
for($i = count($AR)-1 ; $i >= 1; $i--) 
   for($j = 0; $j < $i; $j++) {
      if($AR[$j] > $AR[$j+1]) {
          $t = $AR[$j];
          $AR[$j] = $AR[$j+1];
          $AR[$j+1] = $t;
       } //if
   } //for j

Upvotes: 1

user3528269
user3528269

Reputation: 378

If you want to make this one more efficient, you could put the 

count($AR)-1

in your for loop into a variable, since it would be done at every iteration. Well it's a small speedup since count is O(1), but it's something..
Sidenote: there would be side effects if you modify the array while looping over it in php7 example: 

$a = [1,2,3,4];  
$b = 1;   
for ($i = 0;$i<count($a);$i++) {  
unset($a[$i]);  
echo $i . "\n";  
}  
var_dump($a);

output:

0
1

-:9:
array(2) {
[2] =>
int(3)
[3] =>
int(4)
}

note how it only goes to 1

Upvotes: 1

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