1-Two-Sum.php

class Solution {
    public function twoSum($nums, $target) {
        $map = [];
        for ($i = 0; $i < count($nums); $i++) {
            $complement = $target - $nums[$i];
            if (isset($map[$complement])) {
                return [$map[$complement], $i];
            }
            $map[$nums[$i]] = $i;
        }
        return [];
    }
}