我在后台做一份选择题问卷。对于一个问题，你可以有两种类型的答案:强制性的和可选的。棘手的部分是关于可选答案。
例如:你有4个可选的答案"c||b||a| d"。首先，我需要对它们进行排序以限制解决方案的数量，所以我有:"a||b||c||d"(这部分还可以，只需要排序;))
现在，这是我需要的解决方案:
a
b
c
d
--------
a+b
a+c
a+d
b+c
b+d
c+d
--------
a+b+c
a+b+d
a+c+d
b+c+d
--------
a+b+c+d
目前，我所尝试的是:
$listIdOptionnal = array('a', 'b', 'c', 'd');
$tmpListMatrice = array();
//lette courante
for($i = 0; $i < sizeof($listIdOptionnal); $i++)
{
$tmpListMatrice[] = $listIdOptionnal[$i];
//position suivante
for($j = $i+1; $j < sizeof($listIdOptionnal); $j++)
{
//$tmpListMatrice[] = $listIdOptionnal[$i].','.$listIdOptionnal[$j];
//Longueur
for($k = 1; $k < sizeof($listIdOptionnal); $k++)
{
$tmp = array_slice($listIdOptionnal, $j, $k);
$tmpListMatrice[] = $listIdOptionnal[$i].','.implode(',', $tmp);
}
}
}
$tmpListMatrice = array_unique($tmpListMatrice);
var_dump($tmpListMatrice);exit;
我当前的结果:
array(14) {
[0]=>
string(1) "a"
[1]=>
string(3) "a,b"
[2]=>
string(5) "a,b,c"
[3]=>
string(7) "a,b,c,d"
[4]=>
string(3) "a,c"
[5]=>
string(5) "a,c,d"
[7]=>
string(3) "a,d"
[10]=>
string(1) "b"
[11]=>
string(3) "b,c"
[12]=>
string(5) "b,c,d"
[14]=>
string(3) "b,d"
[17]=>
string(1) "c"
[18]=>
string(3) "c,d"
[21]=>
string(1) "d"
}
正如你所看到的，我的解决方案不是很好，因为这里缺少"a, b, d"
试试这个:
$array = array('a', 'b', 'c', 'd');
$cnt = count($array);
$return = array();
for($i = 1; $i < (1 << $cnt); $i++) {
$str = '';
for($j = 0; $j < $cnt; $j++)
if($i & (1 << $j))
$str .= $array[$j] . ',';
$return[] = $str;
}
foreach ($return as $key=>$elmt)
$return[$key] = substr($elmt, 0, -1);
var_dump($return);
输出:
array (size=15)
0 => string 'a' (length=1)
1 => string 'b' (length=1)
2 => string 'a,b' (length=3)
3 => string 'c' (length=1)
4 => string 'a,c' (length=3)
5 => string 'b,c' (length=3)
6 => string 'a,b,c' (length=5)
7 => string 'd' (length=1)
8 => string 'a,d' (length=3)
9 => string 'b,d' (length=3)
10 => string 'a,b,d' (length=5)
11 => string 'c,d' (length=3)
12 => string 'a,c,d' (length=5)
13 => string 'b,c,d' (length=5)
14 => string 'a,b,c,d' (length=7)
这是我的长版本，
// create new combination
function createCombo($combo, $key){
$combo = explode(",", $combo);
$combo[] = $key;
sort($combo);
return implode(",", $combo);
}
// Recursive function
function getCombos($combos, $keys, $repeat) {
foreach ($combos as $combo){
foreach ($keys as $key){
// key exists in current combination => skip
if (strpos($combo, $key) !== false) continue;
// create new combination
$new = createCombo($combo, $key);
// combination exists => skip
if (in_array($new, $combos)) continue;
// combination not exists => add
$combos[] = $new;
}
}
if (!$repeat--) return $combos;
return getCombos($combos, $keys, $repeat);
}
$keys = array('a','b','c','d');
$combos = getCombos($keys, $keys, count($keys));