数组中取N个值相加等于某个固定值的所有组合

Question

例如
一组数[1,2,3,4,5,6,7,9,10]
计算所有相加值等于12的所有组合
3,9
2,10
2,3,5
6,4,2
1,2,3,6
1,2,4,5

Answer 1

$arr = [1,2,3,4,5,6,7,8,9,10];
$sum = 12;
$len = count($arr);
$data = [];
function s($arr,&$data=[],$i=0,$length=0){
    $len = count($data);
    for($j=$length;$j<$len;$j++){
        foreach($arr as $k=>$v){
            if($k+$i+1<count($arr)){
                $str = $arr[$k+$i+1];
                $sa = explode(',',$data[$j]);
                foreach($sa as $item){
                    if($item > $str){
                        continue 2;
                    }
                }
                if(in_array($str,$sa)){
                    continue;
                }else{
                    if(implode(",",$sa) == ""){
                        continue;
                    }else{
                        $s = implode(",",$sa).",".$str;
                        $data[] = $s;
                    }
                }
            }else{
                break;
            }
        }
    }    $i++;
    if($i>count($arr)){
        return $data;
    }else{
        return s($arr,array_unique($data),$i,$len);
    }
}
echo "<pre >";
$data = s($arr,$arr);
//帅选满足条件的数组
function gf($data,$sum)
{
    echo count($data)."--c<br />";
    $newData = [];
    foreach($data as $k=>$v){
        $a = explode(",",$v);
        $sums = array_sum($a);
        //echo $sums."<br />";
        if($sums == $sum){
            $newData[] = $v;
        }else{
            continue;
        }
    }
    return $newData;
}
echo "<pre >";
$datas = gf($data,$sum);
var_dump($datas);自己组装成一个函数吧 这是考验 最难的都解决了