Online PHP editor | refs for 2OjR5

<?php function computeCombination(array $source,$picks,$startIndex=0,array $pad=array()) { if($picks<=0) { return array($pad); } elseif($picks>=count($source)-$startIndex) { return array(array_merge($pad,array_slice($source,$startIndex))); } $result=array(); foreach(range($startIndex,count($source)-$picks) as $subStartIndex) { $subPad=$pad; $subPad[]=$source[$subStartIndex]; if(empty($pad))// to make the output look nice { $result=array_merge($result,computeCombination($source,$picks-1,$subStartIndex+1,$subPad)); } else { $result=array_merge($result,array(computeCombination($source,$picks-1,$subStartIndex+1,$subPad))); } } return $result; } print_r(computeCombination(array(1,2,3,4,5),2));