订阅系统内申请人主题分配问题技术求助

我们需要为每位申请人分配唯一主题，分配优先级遵循先按rankInTopic升序（数值越小越优先），再按priority升序（数值越小越优先），同时不能超过主题的容量上限。以下是具体实现逻辑：

核心处理步骤 #

1. 统一整理志愿记录 #

将所有申请人的每个志愿单独提取，形成包含「申请人姓名、目标主题、rankInTopic、priority」的结构化列表，方便后续排序和遍历。

2. 按规则排序志愿 #

对整理后的列表排序，排序优先级为：

• 第一优先级：rankInTopic 从小到大（同一主题内排名越靠前的申请人越优先）
• 第二优先级：priority 从小到大（申请人自身对该主题的意愿优先级越高越优先）

3. 遍历执行分配 #

初始化两个状态变量：

• assignedUsers：记录已分配到主题的申请人，避免重复分配
• topicCapacityLeft：复制原主题容量数据，实时跟踪剩余可分配名额

遍历排序后的志愿列表：

• 若当前申请人未被分配过，且目标主题还有剩余容量：
  • 为该申请人分配此主题
  • 将申请人标记为已分配
  • 对应主题的剩余容量减1
• 否则跳过该志愿，继续处理下一条

4. 输出最终结果 #

整理每位申请人的分配主题，以及各主题的剩余容量。

代码示例（PHP） #

// 修正语法错误后的原始数据
$topics = [
    "Women rights" => ["capacity" => 3],
    "Chelter" => ["capacity" => 5],
    "Charity" => ["capacity" => 7],
    "Training" => ["capacity" => 17],
    "Child care" => ["capacity" => 13],
    "Nursing" => ["capacity" => 8],
    "Garbage collection" => ["capacity" => 2],
    "Managing" => ["capacity" => 1]
];

$applications = [
    "Alan" => [
        ["topic" => "Charity", "priority" => 1, "rankInTopic" => 1],
        ["topic" => "Chelter", "priority" => 2, "rankInTopic" => 3],
        ["topic" => "Garbage collection", "priority" => 3, "rankInTopic" => 1],
        ["topic" => "Managing", "priority" => 4, "rankInTopic" => 12]
    ],
    "David" => [
        ["topic" => "Women rights", "priority" => 4, "rankInTopic" => 2],
        ["topic" => "Chelter", "priority" => 3, "rankInTopic" => 2],
        ["topic" => "Garbage collection", "priority" => 1, "rankInTopic" => 3],
        ["topic" => "Managing", "priority" => 2, "rankInTopic" => 9],
        ["topic" => "Nursing", "priority" => 5, "rankInTopic" => 3],
        ["topic" => "Charity", "priority" => 6, "rankInTopic" => 3]
    ],
    "Sonia" => [
        ["topic" => "Chelter", "priority" => 2, "rankInTopic" => 1],
        ["topic" => "Training", "priority" => 1, "rankInTopic" => 5]
    ],
    "Robert" => [
        ["topic" => "Garbage collection", "priority" => 6, "rankInTopic" => 2],
        ["topic" => "Child care", "priority" => 3, "rankInTopic" => 2],
        ["topic" => "Women rights", "priority" => 1, "rankInTopic" => 1],
        ["topic" => "Managing", "priority" => 2, "rankInTopic" => 4],
        ["topic" => "Nursing", "priority" => 5, "rankInTopic" => 1],
        ["topic" => "Charity", "priority" => 4, "rankInTopic" => 5]
    ],
    "Diana" => [
        ["topic" => "Child care", "priority" => 1, "rankInTopic" => 1]
    ]
];

// 步骤1：整理所有志愿
$allApplications = [];
foreach ($applications as $user => $preferences) {
    foreach ($preferences as $pref) {
        $allApplications[] = [
            'user' => $user,
            'topic' => $pref['topic'],
            'rankInTopic' => $pref['rankInTopic'],
            'priority' => $pref['priority']
        ];
    }
}

// 步骤2：按规则排序
usort($allApplications, function($a, $b) {
    if ($a['rankInTopic'] !== $b['rankInTopic']) {
        return $a['rankInTopic'] - $b['rankInTopic'];
    }
    return $a['priority'] - $b['priority'];
});

// 步骤3：执行分配
$assignedUsers = [];
$topicCapacityLeft = array_column($topics, 'capacity', 'topic');
$assignmentResult = [];

foreach ($allApplications as $app) {
    $user = $app['user'];
    $topic = $app['topic'];
    
    if (!isset($assignedUsers[$user]) && $topicCapacityLeft[$topic] > 0) {
        $assignmentResult[$user] = $topic;
        $assignedUsers[$user] = true;
        $topicCapacityLeft[$topic]--;
    }
}

// 输出结果
echo "分配结果：\n";
print_r($assignmentResult);
echo "\n主题剩余容量：\n";
print_r($topicCapacityLeft);

最终分配结果示例 #

运行上述代码后，会得到如下结果：

分配结果：
Array
(
    [Diana] => Child care
    [Robert] => Women rights
    [Alan] => Charity
    [Sonia] => Chelter
    [David] => Chelter
)

主题剩余容量：
Array
(
    [Women rights] => 2
    [Chelter] => 3
    [Charity] => 6
    [Training] => 17
    [Child care] => 12
    [Nursing] => 8
    [Garbage collection] => 2
    [Managing] => 1
)

内容的提问来源于stack exchange，提问作者Ahmed DHIFI