减少多维数组的有效方法

Question

我有以下数组需要用内部值总和来减少

0 => array:116 [
  121 => array:3 [
    "number" => 121
    "name" => "Some Name 1"
    "value" => "2.222"
  ]
  116 => array:3 [
    "number" => 116
    "name" => "Some Name 2"
    "value" => "1.111"
  ]
  1 => array:3 [
    "number" => 1
    "name" => "Some Name 3"
    "value" => "1.232"
  ]
]
1 => array:116 [
  121 => array:3 [
    "number" => 121
    "name" => "Some Name 1"
    "value" => "1.111"
  ]
  116 => array:3 [
    "number" => 116
    "name" => "Some Name 2"
    "value" => "2.222"
  ]
  1 => array:3 [
    "number" => 1
    "name" => "Some Name 3"
    "value" => "3.111"
  ]
]

应该是这样的

0 => array:116 [
  121 => array:3 [
    "number" => 121
    "name" => "Some Name 1"
    "value" => "3.333"
  ] 
  116 => array:3 [
    "number" => 116
    "name" => "Some Name 2"
    "value" => "3.333"
  ]
  1 => array:3 [
    "number" => 1
    "name" => "Some Name 3"
    "value" => "4.343"
  ]
]

假设输入数组的长度未定义，但 complexity/nesting 级别最大为 2，根据输入计算结果数组的 efficient/effective 方法是什么。

优化解决方案对 PHP 5.6 和 PHP 7+

有何影响

Answer 1

我更新了功能，以便能够占用很多 children。在 repl 中，我链接了两个，我向数组键的 0 和 1 添加了一个额外的 child。

// Merege $a[0] and $a[1] and sum up the `value` key 

$merge_sum = array_map(function($key, ...$a) {
  $merged = array_merge(...$a);
  $merged['value'] = array_sum(array_column($a, 'value'));
  return [ $key => $merged ];
}, array_keys($a[0]), ...$a);

// // Fix array array keys

$final = array_reduce($merge_sum, function($c, $i) {
  $concat = $c + $i;
  return $concat;
}, []);

var_dump($final);

在这个repl上测试一下； https://repl.it/Id7T/6

Answer 2

从您的示例输入数组看来，所有 numbers 都在每个子数组（121、116、1）中表示。如果您的实际项目并非如此，请使用更多 accurate/realistic 样本数据更新您的问题。

我的方法"cuts down"通过两次多维数组首先根据数字键隔离数据库的列，然后在like-keyed选择中隔离value元素。

代码：(Demo)

$array = [
    [
        121 => [ "number" => 121, "name" => "Some Name 1", "value" => "2.222" ],
        116 => [ "number" => 116, "name" => "Some Name 2", "value" => "1.111" ],
          1 => [ "number" =>   1, "name" => "Some Name 3", "value" => "1.232" ]
    ],
    [
        121 => [ "number" => 121, "name" => "Some Name 1", "value" => "1.111" ],
        116 => [ "number" => 116, "name" => "Some Name 2", "value" => "2.222" ],
          1 => [ "number" =>   1, "name" => "Some Name 3", "value" => "3.111" ]
    ]
];

$all_numbers=array_keys($array[0]);  // generate a 1-dim array of `number` values
foreach($all_numbers as $number){
    $array[0][$number]['value']=array_sum(array_column(array_column($array,$number),'value'));
}
$array=[$array[0]];  // only keep the first subarray's data

var_export($array);

输出：

array (
  0 => 
  array (
    121 => 
    array (
      'number' => 121,
      'name' => 'Some Name 1',
      'value' => 3.333,
    ),
    116 => 
    array (
      'number' => 116,
      'name' => 'Some Name 2',
      'value' => 3.333,
    ),
    1 => 
    array (
      'number' => 1,
      'name' => 'Some Name 3',
      'value' => 4.343,
    ),
  ),
)

减少多维数组的有效方法

Efficient way of reducing multidimensional array

php

arrays

algorithm

reduce

multidimensional-array