Php 将一个数字分配到一系列因素中(就像贪婪算法)

我发现体重范围的不一致 struct 很难处理，但我完全理解为什么需要这样做--以便正确计算个人磅数.

我创建了一个脚本，试图找到最便宜的合格层，记录层数据，从输入权重中减go 范围的最大值，然后重复. 这似乎适用于我创建的所有测试.

代码:(Demo)

function costFromWeight($weight, array $newRules): array {
    $parsed = [];
    foreach ($newRules as $range => $cost) {
        if (sscanf($range, '%d-%d', $min, $max) === 1) {
            $default = [$min, $min, (float) $cost];
        } else {
            $parsed[]  = [$min, $max, (float) $cost];
        }
    }
    
    $result = ['cost' => 0];
    while ($weight > 0) {
        foreach ($parsed as $i => [$min, $max, $cost]) {
            if ($weight <= $max) {
                if (!$i && $weight <= $min) {  // weight is lower than lowest range, use defaults
                    [$min, $max, $cost] = $default;
                }
                break;
            }
        }
        $result[$max] = ($result[$max] ?? 0) + 1;
        $result['cost'] += $cost;
        $weight -= $max;
    }
    return $result;
}

$rules = [
    '1'   => '1.2',
    '5-10'  => '6.25',
    '10-15' => '9.2',
    '15-20' => '10.9',
];

foreach ([49, 47.75, 38, 35, 23, 15, 14, 10.5, 4] as $weight) {
    echo "$weight :: ";
    print_r(costFromWeight($weight, $rules));
    echo "\n---\n";
}

输出:

49 :: Array
(
    [cost] => 28.05
    [20] => 2
    [10] => 1
)

---
47.75 :: Array
(
    [cost] => 28.05
    [20] => 2
    [10] => 1
)

---
38 :: Array
(
    [cost] => 21.8
    [20] => 2
)

---
35 :: Array
(
    [cost] => 20.1
    [20] => 1
    [15] => 1
)

---
23 :: Array
(
    [cost] => 14.5
    [20] => 1
    [1] => 3
)

---
15 :: Array
(
    [cost] => 9.2
    [15] => 1
)

---
14 :: Array
(
    [cost] => 9.2
    [15] => 1
)

---
10.5 :: Array
(
    [cost] => 9.2
    [15] => 1
)

---
4 :: Array
(
    [cost] => 4.8
    [1] => 4
)

---