php – 搜索类似对象的数组

2023年8月25日 224次阅读

给定一个像这样的数组：

$array = array( 
            0 => array (
               0 => 35,
               1 => 30, 
               2 => 39
            ),
            1 => array (
               0 => 20,
               1 => 12, 
               2 => 5
            ),
            ...

            n => array (
               0 => 10,
               1 => 15, 
               2 => 7
            ),
         );

我需要在数组中找到更接近给定参数的条目

find($a, $b, $c) {
  //return the closer entry to the input
}

对于更接近的条目,我的意思是条目具有与输入中给出的值更接近的值,例如,传递(19,13,3)它应该返回$array [1]

我现在进行计算的方法是循环遍历整个数组,保持从-1开始的变量$distance和临时$result变量.对于每个元素,我计算距离

$dist = abs( subarray[0] - $a ) + abs ( subarray[1] - $b ) + abs( subarray[2] - $c )

如果计算出的距离等于-1或低于循环外的变量$distance,我将新距离分配给变量,并将相应的数组保存在$result变量中.在循环结束时,我最终得到了我需要的值.

此外,其中一个值可以为空：例如(19,13,false)仍应返回$array [1],然后计算应忽略缺失的参数 – 在这种情况下,距离计算为

$dist = abs( subarray[0] - $a ) + abs ( subarray[1] - $b );

忽略子阵列[2]和$c的值.

问题是,即使我的代码工作,也需要花费太多时间来执行,因为数组的大小很容易达到数十万个元素.我们仍然在谈论毫秒,但由于各种原因,这仍然是不可接受的.
有没有更有效的方法来进行此搜索以节省一些时间？

最佳答案 一个自定义功能 – 也许有一个更好的方法,但检查出来：

简而言之 ：

搜索所有项目并以百分比查找它检查的数字($mArray [0 … 3])与您给出的数字之间的差异($mNumbersToFind [0 … 3].添加所有三个数字(每个元素)可能性 – 找到最大值 – 保持位置并返回数组.

$array = array( 
            array (
               0 => 13,
               1 => 15, 
               2 => 4
            ),
            array (
               0 => 20,
               1 => 12, 
               2 => 5
            ),

            array (
               0 => 13,
               1 => 3, 
               2 => 15
            ),
         );


$mNumbersToFind = array(13,3,3);

$mFoundArray = find($mNumbersToFind, $array);

echo "mFinalArray : <pre>";
print_r($mFoundArray);


function find($mNumbersToFind, $mArray){

    $mPossibilityMax = count($mNumbersToFind);
    $mBiggestPossibilityElementPosition = 0;
    $mBiggestPossibilityUntilNow = 0;


    foreach($mArray as $index => $current){

        $maxPossibility = 0;

        foreach($current as $subindex => $subcurrent){



            $mTempArray[$index][$subindex]['value'] = $subcurrent - $mNumbersToFind[$subindex];

            $percentChange = (1 - $mTempArray[$index][$subindex]['value'] / $subcurrent) * 100;
            $mTempArray[$index][$subindex]['possibility'] = $percentChange;
            $maxPossibility += $percentChange/$mPossibilityMax;


        }


        $mTempArray[$index]['final_possibility'] = $maxPossibility;

        if($maxPossibility > $mBiggestPossibilityUntilNow){
            $mBiggestPossibilityUntilNow = $maxPossibility;
            $mBiggestPossibilityElementPosition = $index;
        }



    }

    echo "mTempArray : <pre>"; // Remove this - it's just for debug
    print_r($mTempArray); // Remove this - it's just for debug

    return $mArray[$mBiggestPossibilityElementPosition];
}

Debug Output ($mTempArray) :

mTempArray :
Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [value] => 0
                    [possibility] => 100
                )

            [1] => Array
                (
                    [value] => 12
                    [possibility] => 20
                )

            [2] => Array
                (
                    [value] => 1
                    [possibility] => 75
                )

            [final_possibility] => 65
        )

    [1] => Array
        (
            [0] => Array
                (
                    [value] => 7
                    [possibility] => 65
                )

            [1] => Array
                (
                    [value] => 9
                    [possibility] => 25
                )

            [2] => Array
                (
                    [value] => 2
                    [possibility] => 60
                )

            [final_possibility] => 50
        )

    [2] => Array
        (
            [0] => Array
                (
                    [value] => 0
                    [possibility] => 100
                )

            [1] => Array
                (
                    [value] => 0
                    [possibility] => 100
                )

            [2] => Array
                (
                    [value] => 12
                    [possibility] => 20
                )

            [final_possibility] => 73.333333333333
        )

)

Final Output :

mFinalArray : 
Array
(
    [0] => 13
    [1] => 3
    [2] => 15
)
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