PHP - 从笛卡尔积中寻找最佳组合

Question

我正在玩耍并试图从笛卡尔产品中获得最佳组合。

对于笛卡尔积的每个部分，您必须定义，如果最高值或最低值是最佳值。

例如，在数据集$ a中，最佳值应该是最低值，在$ b和$ c中，最佳值应该是最高值。

到目前为止，这是我的代码，但现在我卡住了

<?php

class Optimizer {

// define different sets
public $a = [
    'from' => 1,
    'till' => 10,
    'steps' => 0.5,
    'best' => 'min',
];

public $b = [
    'from' => 20,
    'till' => 40,
    'steps' => 2,
    'best' => 'max',
];

public $c = [
    'from' => 300,
    'till' => 333,
    'steps' => 1,
    'best' => 'max',
];

// get source variable names
public function getSource() {
    return ['a', 'b', 'c'];
}

// generate input data for cartesian product
public function generateOptions() {
    $options = [];

    foreach($this->getSource() as $varName) {
        $data = $this->$varName;
        $options[$varName] = range($data['from'], $data['till'], $data['steps']);
    }

    return $options;
}

// generate cartesian product
public function cartesianProduct() {
    $result = [];
    $options = $this->generateOptions();

    while (list($key, $values) = each($options)) {
        if (empty($values)) {
            continue;
        }

        if (empty($result)) {
            foreach($values as $value) {
                $result[] = [$key => $value];
            }
        }
        else {
            $append = [];

            foreach($result as &$product) {
                $product[$key] = array_shift($values);

                $copy = $product;

                foreach($values as $item) {
                    $copy[$key] = $item;
                    $append[] = $copy;
                }

                array_unshift($values, $product[$key]);
            }

            $result = array_merge($result, $append);
        }
    }

    return $result;
}

// get criteria per set
public function getCriterias() {
    $criterias = [];

    foreach($this->getSource() as $varName) {
        $data = $this->$varName;
        $criterias[$varName] = $data['best'];
    }

    return $criterias;
}

// find best possible combination
public function findOptimum() {
    $criterias = $this->getCriterias();
    $combinations = $this->cartesianProduct();

    // ...
}
}

欢迎任何帮助，所以提前谢谢