PHP：如何獲得一維數組的所有可能的組合？

Question

可能重複：
algorithm that will take numbers or words and find all possible combinations
Combinations, Dispositions and Permutations in PHP

我讀過/試過所以建議答案，這其中沒有一個解決問題的很多

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

如何獲得所有可能的組合？

預期輸出：

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') 

注：我在尋找答案應該包括所有組合和各種不同的安排。例如：'Alpha Beta'和'Beta Alpha'是2個不同的字符串，它們都應該在輸出數組中。

在此先感謝

Answer 1

我相信你的教授將這種解決方案更幸福：

<?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); 

?> 

這解決了它：

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 
)