Question

我有像这样的关联数组

  $arrz1=Array([sss] => Array
    (
        [0] => 315
        [1] => 330
        [2] => 345
        [3] => 315
        [4] => 330
        [5] => 345
        [6] => 360
        [7] => 315
        [8] => 330
        [9] => 345
        [10] => 360
        [11] => 375
    )

[fff] => Array
    (
        [0] => 315
        [1] => 330
        [2] => 345
        [3] => 315
        [4] => 330
        [5] => 345
        [6] => 360
        [7] => 315
        [8] => 330
        [9] => 345
        [10] => 360
        [11] => 375
        [12] => 750
        [13] => 765
        [14] => 780
    )

）

我想实现这一点。提供的数组大小可以变化，每个下一个不应该有前一个所有元素：

Array([0] => Array
    (
        [0] => Array
            (
                [0] => 315
                [1] => 330
                [2] => 345
                [3] => 315
                [4] => 330
                [5] => 345
                [6] => 360
                [7] => 315
                [8] => 330
                [9] => 345
                [10] => 360
                [11] => 375
            )

    )

[1] => Array
    (
        [0] => Array
            (
                [0] => 750
                [1] => 765
                [2] => 780
            )

    )

需要找出最佳时间复杂度最可行的解决方案。所以，获取的结果足够快，可以在相应的截止日期内达到结果。到目前为止，我已经尝试过以下

    $array_key = array(); 
    $array_val = array();
    $mult = array();


    foreach ($arrz1 as $key => $val) {

            $diff = array();
            foreach($val as $val1)
            {
                if(!in_array($val1, $array_val))
                {

                    $diff[] = $val1;
                }
            }
        if(!in_array($key, $array_key))
        {
            $array_key[] = $key;

            //print_r($diff);
            if(!empty($diff))
            {
                $mult[] = array($diff);
                foreach($val as $value)
                {
                      $array_val[] = $value;

                }
            }
            else
            {
                $mult[] = array($val);
                foreach($val as $value)
                {

                        $array_val[] = $value; 
                }
            }
        }
     }

结果是正确的，但时间过长

Answer 1

使用array_diff和array_values函数考虑以下方法：

// $arr is your initial array
$items = array_values($arr);

foreach ($items as $k => &$item) {
    if ($k != 0) $item = array_values(array_diff($item, $items[$k-1]));
}

print_r($items);

输出：

Array
(
    [0] => Array
        (
            [0] => 315
            [1] => 330
            [2] => 345
            [3] => 315
            [4] => 330
            [5] => 345
            [6] => 360
            [7] => 315
            [8] => 330
            [9] => 345
            [10] => 360
            [11] => 375
        )

    [1] => Array
        (
            [0] => 750
            [1] => 765
            [2] => 780
        )
)

Answer 2

因此，更快捷的方法是使用array_diff。您可以保持包含已索引元素的当前状态，并继续将新数组与状态进行比较。

这样做很快，很容易理解。

<?php

$arr = 
[
    'sss' => [315, 330, 345, 125],
    'fff' => [315, 330, 345, 125, 750, 756, 780],
    'eee' => [330, 345, 220, 750]
];

$state = [];

foreach($arr as $key => $item)
{
    $arr[$key] = array_diff($item, $state);
    $state += $arr[$key];
}

var_dump($arr);

这将导致：

array(3) {
  'sss' =>
  array(4) {
    [0] =>
    int(315)
    [1] =>
    int(330)
    [2] =>
    int(345)
    [3] =>
    int(125)
  }
  'fff' =>
  array(3) {
    [4] =>
    int(750)
    [5] =>
    int(756)
    [6] =>
    int(780)
  }
  'eee' =>
  array(1) {
    [2] =>
    int(220)
  }
}

节点：如果已添加项目eee以显示元素内的项目顺序无关紧要。

删除数组中的匹配元素

2 个答案: