php数据结构之简单选择排序

<?php
$array = array(13,15,6,10,20,6,3,19);

$count = count($array);

$n = $e = 0;

for($i = 1; $i < $count; $i++)

{

//find the min item from $i to last

$min_index = $i;

for($j = $i+1; $j < $count; $j++)

{

$n++;

if($array[$j] < $array[$min_index]) $min_index = $j;

}

if($array[$min_index] < $array[$i-1])

{

$e++;

$tmp = $array[$i-1];

$array[$i-1] = $array[$min_index];

$array[$min_index] = $tmp;

}

}

print_r($array);

echo "共循环{$n}次，共执行{$e}次数据交换";

?>

执行结果为：

Array ( [0] => 3 [1] => 6 [2] => 6 [3] => 10 [4] => 13 [5] => 15 [6] => 19 [7] => 20 )
共循环21次，共执行5次数据交换