PHP:如何获得1D阵列的所有可能组合？

Question

可能重复:
算法将采用数字或单词并在PHP中查找所有可能的组合
组合,处置和排列

我已经在SO上阅读/尝试了很多建议的答案,但没有一个能解决问题

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

如何获得所有可能的组合？

预期产量:

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')

注意:我正在寻找的答案应包括所有组合和所有不同的安排.例如:'Alpha Beta'和'Beta Alpha'是两个不同的字符串,两者都应该在输出数组中.

提前致谢

Answer 1

我相信你的教授对这个解决方案会更满意:

<?php

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

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

    for ($i=0; $i<sizeof($arr);$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);

?>

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
)