求一个一维数组中，n个元素的不同组合,并返回该数组

Question

array('a1','b2','c3','d4','e5','x1','y1','z1');
比如以上数组我想要这个数组元素中三个元素的不同组合，例如下
array('a1','b2','c3');
array('a1','b2','d4');
array('a1','b2','e5');
array('a1','b2','x1');
array('a1','b2','y1');
....并最终返回这样一个数组array(array('a1','b2','c3'),
array('a1','b2','d4'),
array('a1','b2','e5'),
array('a1','b2','x1'),
array('a1','b2','y1'),
......
)

Answer 1

把它array('a1','b2','c3','d4','e5','x1','y1','z1');
变成
array(array('a1','b2','c3'),
array('a1','b2','d4'),
array('a1','b2','e5'),
array('a1','b2','x1'),
array('a1','b2','y1'),
......
)

Answer 2

这个意思？$a = array('a1','b2','c3','d4','e5','x1','y1','z1');$r[] = array_slice($a, 0, 2);
for($p=0; $p<count($r); $p++) {
  $v = $r[$p];
  for($i=count($v); $i<count($a); $i++) {
    if(in_array($a[$i], $v)) break;
    $r[] = array_merge($v, array($a[$i]));
  }
}
print_r($r);Array
(
    [0] => Array
        (
            [0] => a1
            [1] => b2
        )    [1] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
        )    [2] => Array
        (
            [0] => a1
            [1] => b2
            [2] => d4
        )    [3] => Array
        (
            [0] => a1
            [1] => b2
            [2] => e5
        )    [4] => Array
        (
            [0] => a1
            [1] => b2
            [2] => x1
        )    [5] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
        )    [6] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
        )    [7] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
        )    [8] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => e5
        )    [9] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => x1
        )    [10] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => y1
        )    [11] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
        )    [12] => Array
        (
            [0] => a1
            [1] => b2
            [2] => e5
            [3] => d4
        )    [13] => Array
        (
            [0] => a1
            [1] => b2
            [2] => x1
            [3] => d4
        )    [14] => Array
        (
            [0] => a1
            [1] => b2
            [2] => x1
            [3] => e5
        )    [15] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => d4
        )    [16] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => e5
        )    [17] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => x1
        )    [18] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
        )    [19] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => e5
        )    [20] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => x1
        )    [21] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => y1
        )    [22] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
        )    [23] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => x1
        )    [24] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => y1
        )    [25] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => z1
        )    [26] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => x1
            [4] => e5
        )    [27] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => y1
            [4] => e5
        )    [28] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => y1
            [4] => x1
        )    [29] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => e5
        )    [30] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => x1
        )    [31] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => y1
        )    [32] => Array
        (
            [0] => a1
            [1] => b2
            [2] => x1
            [3] => d4
            [4] => e5
        )    [33] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => d4
            [4] => e5
        )    [34] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => d4
            [4] => x1
        )    [35] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => x1
            [4] => e5
        )    [36] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => e5
        )    [37] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => x1
        )    [38] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => y1
        )    [39] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => x1
            [4] => e5
        )    [40] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => y1
            [4] => e5
        )    [41] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => y1
            [4] => x1
        )    [42] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => x1
        )    [43] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => y1
        )    [44] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => z1
        )    [45] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => y1
            [5] => x1
        )    [46] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => z1
            [5] => x1
        )    [47] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => z1
            [5] => y1
        )    [48] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => y1
            [4] => e5
            [5] => x1
        )    [49] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => e5
            [5] => x1
        )    [50] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => e5
            [5] => y1
        )    [51] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => y1
            [5] => x1
        )    [52] => Array
        (
            [0] => a1
            [1] => b2
            [2] => y1
            [3] => d4
            [4] => e5
            [5] => x1
        )    [53] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => e5
            [5] => x1
        )    [54] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => e5
            [5] => y1
        )    [55] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => y1
            [5] => x1
        )    [56] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => y1
            [4] => e5
            [5] => x1
        )    [57] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => x1
            [6] => y1
        )    [58] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => x1
            [6] => z1
        )    [59] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => z1
            [6] => y1
        )    [60] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => z1
            [5] => x1
            [6] => y1
        )    [61] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => z1
            [4] => e5
            [5] => x1
            [6] => y1
        )    [62] => Array
        (
            [0] => a1
            [1] => b2
            [2] => z1
            [3] => d4
            [4] => e5
            [5] => x1
            [6] => y1
        )    [63] => Array
        (
            [0] => a1
            [1] => b2
            [2] => c3
            [3] => d4
            [4] => e5
            [5] => x1
            [6] => y1
            [7] => z1
        ))