數組演算法解決思路

數組演算法
Array
(
[0] => Array
(
[0] => 1
[1] => 2
)

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

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

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

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

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

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

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

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

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

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

[11] => Array
(
[0] => 20
[1] => 30
)

[12] => Array
(
[0] => 35
[1] => 25
)

[13] => Array
(
[0] => 100
[1] => 15
)
[14] => Array
(
[0] => 2
[1] => 1
)

)
目的：裡面有重複的只保留一個，然後資料是全部都是唯一的。倒過來的也認為是重複的，譬如1,2和2,1也當作是重複的。。
自己寫了個演算法。覺得效率太慢了。。大家還有好的演算法不？

------解決方案--------------------
array_unique()
------解決方案--------------------
foreach($inputarray as $value) {
foreach($value as $key=>$v) {
$newarray[$v] = $key;
}
}
$array = array_keys($newarray);
print_r($array);

