array_chunk，防止重复块

Question

我有很多人，比如说：

$a = ['John', 'Amy', 'Bill', 'Jim']

数组可以有4个以上的元素。

我需要为每个元素与同一数组中的另一个元素生成2个配对，而不生成重复配对(在可以避免的情况下)，也不需要将一个元素与其自身配对：

    Array
(
[0] => Array
    (
        [0] => John
        [1] => Amy
    )


[1] => Array
    (
        [0] => Amy
        [1] => Bill
    )

[2] => Array
    (
        [0] => Bill
        [1] => Jim
    )

[3] => Array
    (
        [0] => John
        [1] => Jim
    )

)

我尝试过一些草率的技术，例如复制数组，将两者合并，并将它们分块成对。重复配对，相同的元素配对不断出现，所以在合并和分块数组之前，我已经尝试过像shuffle($duplicated_array)和array_reverse($duplicated_array)这样的东西，仍然可以存在重复配对。

为数组中的每个元素生成2对而不创建重复配对或与其自身配对的正确方法是什么？

提前谢谢。

下面是一个不完全防止重复的尝试的例子：

$duplicate_array = $a;
        shuffle($duplicate_array);
        $combined = array_merge($duplicate_array, $a);
        $combined = array_chunk($combined,2);

Answer 1

只需做两个循环，并简单地检查名称是否相同。

<?php
$arr = ['John', 'Amy', 'Bill', 'Jim'];

$result = [];
foreach ($arr as $a) {
    foreach ($arr as $b) {
        if ($a === $b) continue;
        $result[] = [$a, $b];
    } 
}

print_r($result);

结果：

Array
(
    [0] => Array
        (
            [0] => John
            [1] => Amy
        )

    [1] => Array
        (
            [0] => John
            [1] => Bill
        )

    [2] => Array
        (
            [0] => John
            [1] => Jim
        )

    [3] => Array
        (
            [0] => Amy
            [1] => John
        )

    [4] => Array
        (
            [0] => Amy
            [1] => Bill
        )

    [5] => Array
        (
            [0] => Amy
            [1] => Jim
        )

    [6] => Array
        (
            [0] => Bill
            [1] => John
        )

    [7] => Array
        (
            [0] => Bill
            [1] => Amy
        )

    [8] => Array
        (
            [0] => Bill
            [1] => Jim
        )

    [9] => Array
        (
            [0] => Jim
            [1] => John
        )

    [10] => Array
        (
            [0] => Jim
            [1] => Amy
        )

    [11] => Array
        (
            [0] => Jim
            [1] => Bill
        )

)

想要一个中间名，添加3个循环等等。

<?php
$arr = ['John', 'Amy', 'Bill', 'Jim'];

$result = [];
foreach ($arr as $a) {
    foreach ($arr as $b) {
        if ($a === $b) continue;
        foreach ($arr as $c) {
            if ($a === $c || $b === $c) continue;
            $result[] = [$a, $b, $c];
        }
    } 
}

print_r($result);

Answer 2

可以将每个名称与数组中的下列名称配对。

$names = ['John', 'Amy', 'Bill', 'Jim'];

$n = count($names);
foreach ($names as $index => $name) {
    $pairs[] = [$name, $names[($index + 1) % $n]];
}

如果这两对需要随机化，那么在进行配对之前，您可以先对名字进行洗牌。