PHP一维数组组合穷举方法不重复组合（组合首选）

<?php
/**
 * @param $arr 需要组合数组
 * @param int $num 组合元素个数
 * @return array
 */
function getSequenceAry($arr,$num=1)
{
    $count = count($arr);
    $min   = min($count,$num);

    if($min<1){
        return false;
    }

    $return =array();
    for(;$min>=1;$min--){
//此处如果改成for(;$min>1;$min--)只输出随机取出两个元素的重复组合
        $arrRet = array();
        $max = $count-($min-1);
        for($i=0;$i<$max;$i++){
            getSequenceArySub($arr,$count,$min,$i,$arrRet,$return);

        }
    }
    return $return;

}

function getSequenceArySub($arr,$count,$min,$i,$arrRet=array(),& $return){
    if(empty($arr) || empty($count))
        return false;
    if(1==$min){
        $arrRet[--$min] = $arr[$i];
        $return[] = $arrRet;
    }else{
        $arrRet[--$min] = $arr[$i];
        for($j = $i+1;$j<($count);$j++){
            getSequenceArySub($arr,$count,$min,$j,$arrRet,$return);
        }
    }
}

print_r(getSequenceAry(array(1,2,3,4,5),1));
print_r(getSequenceAry(array(1,2,3,4,5),2));
print_r(getSequenceAry(array(1,2,3,4,5),3));
print_r(getSequenceAry(array(1,2,3,4,5),4));
print_r(getSequenceAry(array(1,2,3,4,5),5));
?>


结果：

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

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

    [2] => Array
        (
            [0] => 3
        )

    [3] => Array
        (
            [0] => 4
        )

    [4] => Array
        (
            [0] => 5
        )

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

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

    [2] => Array
        (
            [1] => 1
            [0] => 4
        )

    [3] => Array
        (
            [1] => 1
            [0] => 5
        )

    [4] => Array
        (
            [1] => 2
            [0] => 3
        )

    [5] => Array
        (
            [1] => 2
            [0] => 4
        )

    [6] => Array
        (
            [1] => 2
            [0] => 5
        )

    [7] => Array
        (
            [1] => 3
            [0] => 4
        )

    [8] => Array
        (
            [1] => 3
            [0] => 5
        )

    [9] => Array
        (
            [1] => 4
            [0] => 5
        )

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

    [11] => Array
        (
            [0] => 2
        )

    [12] => Array
        (
            [0] => 3
        )

    [13] => Array
        (
            [0] => 4
        )

    [14] => Array
        (
            [0] => 5
        )

)
Array
(
    [0] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 3
        )

    [1] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 4
        )

    [2] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 5
        )

    [3] => Array
        (
            [2] => 1
            [1] => 3
            [0] => 4
        )

    [4] => Array
        (
            [2] => 1
            [1] => 3
            [0] => 5
        )

    [5] => Array
        (
            [2] => 1
            [1] => 4
            [0] => 5
        )

    [6] => Array
        (
            [2] => 2
            [1] => 3
            [0] => 4
        )

    [7] => Array
        (
            [2] => 2
            [1] => 3
            [0] => 5
        )

    [8] => Array
        (
            [2] => 2
            [1] => 4
            [0] => 5
        )

    [9] => Array
        (
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [10] => Array
        (
            [1] => 1
            [0] => 2
        )

    [11] => Array
        (
            [1] => 1
            [0] => 3
        )

    [12] => Array
        (
            [1] => 1
            [0] => 4
        )

    [13] => Array
        (
            [1] => 1
            [0] => 5
        )

    [14] => Array
        (
            [1] => 2
            [0] => 3
        )

    [15] => Array
        (
            [1] => 2
            [0] => 4
        )

    [16] => Array
        (
            [1] => 2
            [0] => 5
        )

    [17] => Array
        (
            [1] => 3
            [0] => 4
        )

    [18] => Array
        (
            [1] => 3
            [0] => 5
        )

    [19] => Array
        (
            [1] => 4
            [0] => 5
        )

    [20] => Array
        (
            [0] => 1
        )

    [21] => Array
        (
            [0] => 2
        )

    [22] => Array
        (
            [0] => 3
        )

    [23] => Array
        (
            [0] => 4
        )

    [24] => Array
        (
            [0] => 5
        )

)
Array
(
    [0] => Array
        (
            [3] => 1
            [2] => 2
            [1] => 3
            [0] => 4
        )

    [1] => Array
        (
            [3] => 1
            [2] => 2
            [1] => 3
            [0] => 5
        )

    [2] => Array
        (
            [3] => 1
            [2] => 2
            [1] => 4
            [0] => 5
        )

    [3] => Array
        (
            [3] => 1
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [4] => Array
        (
            [3] => 2
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [5] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 3
        )

    [6] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 4
        )

    [7] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 5
        )

    [8] => Array
        (
            [2] => 1
            [1] => 3
            [0] => 4
        )

    [9] => Array
        (
            [2] => 1
            [1] => 3
            [0] => 5
        )

    [10] => Array
        (
            [2] => 1
            [1] => 4
            [0] => 5
        )

    [11] => Array
        (
            [2] => 2
            [1] => 3
            [0] => 4
        )

    [12] => Array
        (
            [2] => 2
            [1] => 3
            [0] => 5
        )

    [13] => Array
        (
            [2] => 2
            [1] => 4
            [0] => 5
        )

    [14] => Array
        (
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [15] => Array
        (
            [1] => 1
            [0] => 2
        )

    [16] => Array
        (
            [1] => 1
            [0] => 3
        )

    [17] => Array
        (
            [1] => 1
            [0] => 4
        )

    [18] => Array
        (
            [1] => 1
            [0] => 5
        )

    [19] => Array
        (
            [1] => 2
            [0] => 3
        )

    [20] => Array
        (
            [1] => 2
            [0] => 4
        )

    [21] => Array
        (
            [1] => 2
            [0] => 5
        )

    [22] => Array
        (
            [1] => 3
            [0] => 4
        )

    [23] => Array
        (
            [1] => 3
            [0] => 5
        )

    [24] => Array
        (
            [1] => 4
            [0] => 5
        )

    [25] => Array
        (
            [0] => 1
        )

    [26] => Array
        (
            [0] => 2
        )

    [27] => Array
        (
            [0] => 3
        )

    [28] => Array
        (
            [0] => 4
        )

    [29] => Array
        (
            [0] => 5
        )

)
Array
(
    [0] => Array
        (
            [4] => 1
            [3] => 2
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [1] => Array
        (
            [3] => 1
            [2] => 2
            [1] => 3
            [0] => 4
        )

    [2] => Array
        (
            [3] => 1
            [2] => 2
            [1] => 3
            [0] => 5
        )

    [3] => Array
        (
            [3] => 1
            [2] => 2
            [1] => 4
            [0] => 5
        )

    [4] => Array
        (
            [3] => 1
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [5] => Array
        (
            [3] => 2
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [6] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 3
        )

    [7] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 4
        )

    [8] => Array
        (
            [2] => 1
            [1] => 2
            [0] => 5
        )

    [9] => Array
        (
            [2] => 1
            [1] => 3
            [0] => 4
        )

    [10] => Array
        (
            [2] => 1
            [1] => 3
            [0] => 5
        )

    [11] => Array
        (
            [2] => 1
            [1] => 4
            [0] => 5
        )

    [12] => Array
        (
            [2] => 2
            [1] => 3
            [0] => 4
        )

    [13] => Array
        (
            [2] => 2
            [1] => 3
            [0] => 5
        )

    [14] => Array
        (
            [2] => 2
            [1] => 4
            [0] => 5
        )

    [15] => Array
        (
            [2] => 3
            [1] => 4
            [0] => 5
        )

    [16] => Array
        (
            [1] => 1
            [0] => 2
        )

    [17] => Array
        (
            [1] => 1
            [0] => 3
        )

    [18] => Array
        (
            [1] => 1
            [0] => 4
        )

    [19] => Array
        (
            [1] => 1
            [0] => 5
        )

    [20] => Array
        (
            [1] => 2
            [0] => 3
        )

    [21] => Array
        (
            [1] => 2
            [0] => 4
        )

    [22] => Array
        (
            [1] => 2
            [0] => 5
        )

    [23] => Array
        (
            [1] => 3
            [0] => 4
        )

    [24] => Array
        (
            [1] => 3
            [0] => 5
        )

    [25] => Array
        (
            [1] => 4
            [0] => 5
        )

    [26] => Array
        (
            [0] => 1
        )

    [27] => Array
        (
            [0] => 2
        )

    [28] => Array
        (
            [0] => 3
        )

    [29] => Array
        (
            [0] => 4
        )

    [30] => Array
        (
            [0] => 5
        )

)