twoSum-2

class Solution {
    public function twoSum(array $nums, int $target) {
        $c = count($nums);
        #$n = array_combine( array_values($nums), array_keys($nums) );
        $n = [];
        for($i=0;$i<$c;$i++){
            $x = $target - $nums[$i];
            if(array_key_exists($x, $n)){
                return [ $n[$x], $i  ];
            }
            $n[$nums[$i]] = $i;
        }
        return [];
    }
}