如何定义一个方程来根据权重计算对象（餐厅）的排名

Question

我有一系列餐厅，我需要根据这些规则计算每家餐厅的排名：

与我的距离（公里）(weight=30)
赞(weight=10)

$restaurants = [
 {name: "KFC", distance: 17, likes: 3},
 {name: "Macdonalds", distance: 2, likes: 9},
 {name: "Pizza Hut", distance: 9, likes: 12},
 {name: "Burger King", distance: 14, likes: 17},
];

排名越高意味着这家餐厅离我越近，并且根据方程获得更多的赞。

方程应该是什么？

Answer 1

这是您的问题的一种可能解决方案。我们使用权重数组，其键与 restaurants 数组中的键匹配，值如您的问题所示。请注意，对于距离，我们使用负值，因为您希望距离较近的餐厅（距离值越小）排名越高。然后我们可以根据每个权重的评分总和对餐厅数组进行排序：

function get_rating($restaurant, $weights) {
    $rating = 0;
    foreach ($weights as $factor => $weight) {
        $rating += $weight * $restaurant[$factor];
    }
    return $rating;
}

$weights = array('distance' => -30, 'likes' => 10);

usort($restaurants, function ($a, $b) use ($weights) {
    return get_rating($b, $weights) - get_rating($a, $weights);
});

print_r($restaurants);

输出：

Array
(
    [0] => Array
        (
            [name] => Macdonalds
            [distance] => 2
            [likes] => 9
        )
    [1] => Array
        (
            [name] => Pizza Hut
            [distance] => 9
            [likes] => 12
        )
    [2] => Array
        (
            [name] => Burger King
            [distance] => 14
            [likes] => 17
        )
    [3] => Array
        (
            [name] => KFC
            [distance] => 17
            [likes] => 3
        )
)

Demo on 3v4l.org

请注意，您问题中的 $restaurants 变量不是有效的 PHP 结构；我假设你有一个关联数组。

如何定义一个方程来根据权重计算对象（餐厅）的排名

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