Online PHP editor | refs for LYhH6

<?php function numberOfPairs($a,$k){ $a=array_count_values($a); // enable use of the very fast isset() function and avoid iterating duplicates ksort($a); // order so that only the lower values need to be iterated foreach($a as $num=>$occur){ if(($double=$num*2)>=$k){ // we are at or past the middle if($double==$k && $occur>1) $result[]=[$num,$k-$num]; // addends are equal and 2 exist, store before break break; }elseif(isset($a[$k-$num])){ // matching addend found, store & continue $result[]=[$num,$k-$num]; } } var_export($result); } $a = [6,6,3,9,3,5,1]; $k = 12; numberOfPairs($a,$k);