PHP：如何获得一维数组的所有可能组合？

PHP: How to get all possible combinations of 1D array?

提问by evilReiko

Possible Duplicate:
algorithm that will take numbers or words and find all possible combinations
Combinations, Dispositions and Permutations in PHP

可能的重复：
算法将采用数字或单词并在 PHP 中找到所有可能的组合
组合、排列和排列

I've read/tried alot of the suggested answers on SO, which none of them solves the problem

我已经阅读/尝试了很多关于 SO 的建议答案，但没有一个能解决问题

$array = array('Alpha', 'Beta', 'Gamma');

How to get all possible combinations?

如何获得所有可能的组合？

Expected output:

预期输出：

array('Alpha',
      'Beta',
      'Gamma',
      'Alpha Beta',
      'Alpha Gamma',
      'Beta Alpha',
      'Beta Gamma',
      'Gamma Alpha',
      'Gamma Beta',
      'Alpha Beta Gamma',
      'Alpha Gamma Beta',
      'Beta Alpha Gamma',
      'Beta Gamma Alpha',
      'Gamma Alpha Beta',
      'Gamma Beta Alpha')

Note: The answer I'm looking for should include all combinations and all different arrangements. For example: 'Alpha Beta'and 'Beta Alpha'are 2 different strings and both should be in the output array.

注意：我正在寻找的答案应该包括所有组合和所有不同的安排。例如：'Alpha Beta'和'Beta Alpha'是 2 个不同的字符串，都应该在输出数组中。

Thanks in advance

提前致谢

回答by abcde123483

I believe your professor will be happier with this solution:

我相信你的教授会对这个解决方案更满意：

<?php

$array = array('Alpha', 'Beta', 'Gamma', 'Sigma');

function depth_picker($arr, $temp_string, &$collect) {
    if ($temp_string != "") 
        $collect []= $temp_string;

    for ($i=0, $iMax = sizeof($arr); $i < $iMax; $i++) {
        $arrcopy = $arr;
        $elem = array_splice($arrcopy, $i, 1); // removes and returns the i'th element
        if (sizeof($arrcopy) > 0) {
            depth_picker($arrcopy, $temp_string ." " . $elem[0], $collect);
        } else {
            $collect []= $temp_string. " " . $elem[0];
        }   
    }   
}

$collect = array();
depth_picker($array, "", $collect);
print_r($collect);

?>

This solves it:

这解决了它：

Array
(
    [0] =>  Alpha
    [1] =>  Alpha Beta
    [2] =>  Alpha Beta Gamma
    [3] =>  Alpha Beta Gamma Sigma
    [4] =>  Alpha Beta Sigma
    [5] =>  Alpha Beta Sigma Gamma
    [6] =>  Alpha Gamma
    [7] =>  Alpha Gamma Beta
    [8] =>  Alpha Gamma Beta Sigma
    [9] =>  Alpha Gamma Sigma
    [10] =>  Alpha Gamma Sigma Beta
    [11] =>  Alpha Sigma
    [12] =>  Alpha Sigma Beta
    [13] =>  Alpha Sigma Beta Gamma
    [14] =>  Alpha Sigma Gamma
    [15] =>  Alpha Sigma Gamma Beta
    [16] =>  Beta
    [17] =>  Beta Alpha
    [18] =>  Beta Alpha Gamma
    [19] =>  Beta Alpha Gamma Sigma
    [20] =>  Beta Alpha Sigma
    [21] =>  Beta Alpha Sigma Gamma
    [22] =>  Beta Gamma
    [23] =>  Beta Gamma Alpha
    [24] =>  Beta Gamma Alpha Sigma
    [25] =>  Beta Gamma Sigma
    [26] =>  Beta Gamma Sigma Alpha
    [27] =>  Beta Sigma
    [28] =>  Beta Sigma Alpha
    [29] =>  Beta Sigma Alpha Gamma
    [30] =>  Beta Sigma Gamma
    [31] =>  Beta Sigma Gamma Alpha
    [32] =>  Gamma
    [33] =>  Gamma Alpha
    [34] =>  Gamma Alpha Beta
    [35] =>  Gamma Alpha Beta Sigma
    [36] =>  Gamma Alpha Sigma
    [37] =>  Gamma Alpha Sigma Beta
    [38] =>  Gamma Beta
    [39] =>  Gamma Beta Alpha
    [40] =>  Gamma Beta Alpha Sigma
    [41] =>  Gamma Beta Sigma
    [42] =>  Gamma Beta Sigma Alpha
    [43] =>  Gamma Sigma
    [44] =>  Gamma Sigma Alpha
    [45] =>  Gamma Sigma Alpha Beta
    [46] =>  Gamma Sigma Beta
    [47] =>  Gamma Sigma Beta Alpha
    [48] =>  Sigma
    [49] =>  Sigma Alpha
    [50] =>  Sigma Alpha Beta
    [51] =>  Sigma Alpha Beta Gamma
    [52] =>  Sigma Alpha Gamma
    [53] =>  Sigma Alpha Gamma Beta
    [54] =>  Sigma Beta
    [55] =>  Sigma Beta Alpha
    [56] =>  Sigma Beta Alpha Gamma
    [57] =>  Sigma Beta Gamma
    [58] =>  Sigma Beta Gamma Alpha
    [59] =>  Sigma Gamma
    [60] =>  Sigma Gamma Alpha
    [61] =>  Sigma Gamma Alpha Beta
    [62] =>  Sigma Gamma Beta
    [63] =>  Sigma Gamma Beta Alpha
)