PHP custom method, how to find unique data composed of three elements in an array-PHP Tutorial-php.cn

PHP custom method, how to find unique data composed of three elements in an array

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Release： 2016-07-06 13:52:50

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An example of the
array is as follows:
[123,345,567,1235,6435,77,33,444,555,666,111,999,19,101,5542]

It is necessary to find all the combinations composed of the elements (three) in this array. The combinations are as follows

123, 345, 567
1235,6435,77
33,444,555
666,111,999
111,999,19
. . .
n Multiple combinations, each combination is non-repeating (this can be the case 123, 345, 567 345, 123, 567, that is, the order is different)

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An example of the
array is as follows:
[123,345,567,1235,6435,77,33,444,555,666,111,999,19,101,5542]

It is necessary to find all the combinations composed of the elements (three) in this array. The combinations are as follows

Example:

<code><?php

$data = [123, 345, 567, 1235, 6435, 77, 33, 444, 444, 123, 555, 666, 111, 999, 19, 101, 5542];

// 生成
$items = generate($data);
foreach ($items as $item) {
    echo implode("\t", $item) . PHP_EOL;
}

function generate($data)
{
    // 排序
    sort($data);

    // 去重
    $data = array_unique($data);
    $data = array_values($data);

    // 打印原始字符串
    echo implode(", ", $data) . PHP_EOL . PHP_EOL;

    $items = [];
    for ($i = 0; $i < count($data); $i++) {
        for ($j = 0; $j < count($data); $j++) {
            if ($j == $i) {
                continue;
            }
            for ($k = 0; $k < count($data); $k++) {
                if ($k == $j || $k == $i) {
                    continue;
                }
                $items[] = [$data[$i], $data[$j], $data[$k]];
            }
        }
    }

    return $items;
}</code>

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The whole combination is upstairs, I will add a full arrangement

https://3v4l.org/n4ZXT

Reference: Full arrangement and full combination implementation

Please tell me, can anyone help me

<code><?php

function getCombinationToString($arr, $m) {
    if ($m == 1) {
       return $arr;
    }
    $result = [];
    
    $tmpArr = $arr;
    unset($tmpArr[0]);
    for($i = 0; $i < count($arr); $i++) {
        $s = $arr[$i];
        $ret = getCombinationToString(array_values($tmpArr), ($m - 1), $result);
        foreach($ret as $row) {
            $val = $s . ',' . $row;
            $val = explode(',', $val);
            sort($val);
            $val = implode(',', $val);
            if(! in_array($s, explode(',', $row)) && ! in_array($val, $result)) {
                $result[] = $val;
            }
        }
    }   
  return $result;
}

$arr = [123, 345, 567, 1235, 6435, 77, 33, 444, 555, 666, 111, 999, 19, 101, 5542];

$t = getCombinationToString($arr, 3);
echo '<pre class="brush:php;toolbar:false">';print_r($t);</code>

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