php - 如何按数组定义的特定顺序对大量项目进行排序？

Question

我需要实现一些特定的排序算法。我有两个数组:

$items = array(
  array("id" => "…", "type" => "alpha"),
  array("id" => "…", "type" => "beta"),
  array("id" => "…", "type" => "company"),
  array("id" => "…", "type" => "marketing"),
  array("id" => "…", "type" => "beta"),
  array("id" => "…", "type" => "company"),
  array("id" => "…", "type" => "alpha"),
  array("id" => "…", "type" => "alpha"),
  array("id" => "…", "type" => "company"),
  array("id" => "…", "type" => "marketing"),
  […]
);

$order = array("company", "marketing", "alpha", "beta" );

正如您可能想象的那样，我需要根据 $order 中指定的顺序对 $items 进行排序。

Answer 1

运行 $items 并将所有内容索引到使用“type”作为键的字典中。然后运行 ​​$order 并查找对应于该“类型”的项目列表并将它们附加到排序列表中。在 O(n+k) 中运行，k 是 |order|。