Solution.php

<?php

class Solution {

    /**
     * @param Integer[] $nums
     * @param Integer $target
     * @return Integer
     */
    function threeSumClosest($nums, $target) {
        sort($nums);
        $min = 2147483647;
        $res = 0;
        for ($i = 2; $i < count($nums); $i++) {
            $l = 0;
            $r = $i - 1;

            while ($l < $r) {
                $sum = $nums[$l] + $nums[$r] + $nums[$i];
                if ($sum == $target) {
                    return $target;
                }
                $diff = abs($target - $sum);
                if ($diff < $min) {
                    $min = $diff;
                    $res = $sum;
                }
                if ($sum < $target) {
                    $l++;
                } else {
                    $r--;
                }
            }
        }
        return $res;
    }
}