PHP bubble sort, quick sort, quick search, two-dimensional array deduplication example sharing

1. Bubble sort

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

2. Quick sort

//快排
function quick_sort($array)
{
    $count=count($array);
    if($count <= 1){
        return $array;
    }
    $key=$array[0];
    $array_left=array();
    $array_right=array();
    for($i=1;$i<$count;$i++){
        if($array[$i] < $key ){
            $array_left[]=$array[$i];
        }else{
            $array_right[]=$array[$i];
        }
    }
    $array_left=quick_sort($array_left);
    $array_right=quick_sort($array_right);
    return array_merge($array_left,array($key),$array_right);
}
$myarray=array(1,5,3,4,12,10,8);
print_r(bubble_sort($myarray));
echo "<br/>";
print_r(quick_sort($myarray));
echo "<br/>";

3. Quickly find the position where the value first appears

/**
 * 快速查找值第一次出现的位置
 * @param array $array          数组
 * @param string $k             要找的值
 * @param int $low              查找范围的最小键值
 * @param int $high             范围的最大键值   
 */
function search($array, $k, $low=0, $high=0)
{    
 //判断是否为第一次调用   
    if(count($array)!=0 and $high == 0){
        $high = count($array);   
    }
    //如果还存在剩余的数组元素
    if($low <= $high){
     //取$low和$high的中间值
        $mid = intval(($low+$high)/2);
        //如果找到则返回
        if ($array[$mid] == $k){
            return $mid;
        }
        //如果没有找到，则继续查找
        elseif ($k < $array[$mid]){
            return search($array, $k, $low, $mid-1);
        }
        else {
            return search($array, $k, $mid+1, $high);
        }
    }
    return -1;
}
$array = array(4,5,7,8,9,10,8);                  //测试search函数 
echo search($array, 8);                          //调用search函数并输出查找结果

4. Remove duplicates from the two-dimensional array

/**
     * 去掉二维数组中的重复项
     * @param $array2D          数组
     * @param $keyArray         还原时字段对应的key
     * @return array            去掉了重复项的数组
     */
    public function array_unique_fb($array2D,$keyArray){
        $temp=array();
        foreach ($array2D as $v){
            $v = join(",",$v);  //降维,也可以用implode,将一维数组转换为用逗号连接的字符串
            $temp[] = $v;
        }
        $temp = array_unique($temp);    //去掉重复的字符串,也就是重复的一维数组
        foreach ($temp as $k => $v){
            //$temp[$k] = explode(",",$v);   //再将拆开的数组重新组装
           $temp[$k]= array_combine($keyArray ,explode(",",trim($v)));
        }
        return $temp;
    }
 
$testArray=array_unique_fb(array(array('a'=>1,'b'=>2,'c'=>3),
    array('a'=>1,'b'=>2,'c'=>3),array('a'=>1,'b'=>2,'c'=>3)),array('a','b','c''));
print_r($testArray);

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