php冒泡排序和折半查找

$arr = [99, 1, 2, 3, 4, 5, 19, 6, 7, 8, 9];

$arr = paopao($arr);
print_r($arr);

echo binary_search($arr, 6) . PHP_EOL;


//冒泡排序
function paopao($arr)
{
    $count = count($arr);
    for ($i = 0; $i < $count - 1; $i++) {
        for ($j = $i + 1; $j < $count; $j++) {
            if ($arr[$i] > $arr[$j]) {
                $temp = $arr[$i];
                $arr[$i] = $arr[$j];
                $arr[$j] = $temp;
            }
        }
    }
    return $arr;
}


//折半查找
function binary_search($arr, $target)
{
    $left = 0;
    $right = count($arr) - 1;
    while (true) {
        if ($left <= $right) {
            $mid = intval($left + ($right - $left) / 2);
            if ($arr[$mid] == $target) {
                return $mid;
            } elseif ($arr[$mid] < $target) {
                $left = $mid + 1;
            } else {
                $right = $mid - 1;
            }
        }
    }
    return -1;
}