threeSum optimised

threeSum.php

<?php 
class Solution {

    /**
     * @param Integer[] $nums
     * @return Integer[][]
     */
    function threeSum($nums) {
       $results = [];
       $max = count($nums);
       sort($nums);
       
       for ($a = 0;$a < $max;$a++) {
          $first = $nums[$a];
          $m = [];

          for ($b = $a+1;$b < $max;$b++) {
              $second = $nums[$b];
              
              if (array_key_exists($second, $m)) {
                  $match = [$first, $second, $nums[$m[$second]]];
                   if (array_search($match, $results, TRUE) === FALSE) {
                      $results[] = $match;
                   }
              } else {
                   $m[-($first+$second)] = $b;   
              }
            
          }
       
       }
    
    return $results;
    }