".ucwords($title)."

"; echo "The code orders a number array so that it calculates the lowest posible sum of the products of adjacent number
"; function mult_couples($myarray){ $res=0; $count= count($myarray)-1; echo "("; foreach ($myarray as $key => $value) { if($key<$count) { echo $myarray[$key]."*".$myarray[$key+1]; $res+= $myarray[$key]*$myarray[$key+1]; if($key<$count-1) echo ")+("; else echo ")="; } } echo $res."
"; } function mpps($myarray){ sort($myarray); # (1,5,10,25,40) $myarray= array_reverse($myarray); # (40,25,10,5,1) $count= count($myarray)-1; for($i=0,$k=$count;$i<=$count/2;$i++,$k--){ if($i%2){ $aux= $myarray[$k+1]; $myarray[$k+1]= $myarray[$i]; $myarray[$i]= $aux; } } mult_couples($myarray); } # Define arrays ------------------- $array03= array(50,65,20,11,33); $array02= array(10,9,8,7,6,5,3,4,2,1); $myarray= array(40,25,10,5,1); echo "Example = ("; foreach($myarray as $k =>$v){echo $myarray[$k].", ";} echo ")
"; mult_couples($myarray); echo "12"; echo "The expected output is 225
"; echo "The original array:
"; $count= count($myarray)-1; echo "
"; for($i=0,$k=$count;$i<=$count/2;$i++,$k--){ if($i%2){ $aux= $myarray[$k+1]; $myarray[$k+1]= $myarray[$i]; $myarray[$i]= $aux; } print_r($myarray); echo "
"; } echo "
Minimal pair product sum:
"; mpps($myarray); echo "------------------------------
"; echo "Example 2= ("; foreach($array02 as $k =>$v){echo $array02[$k].", ";} echo ")
"; mult_couples($array02); echo "
Minimal pair product sum:
"; mpps($array02); echo "------------------------------
"; echo "Example 3= ("; foreach($array03 as $k =>$v){echo $array03[$k].", ";} echo ")
"; mult_couples($array03); echo "
Minimal pair product sum:
"; mpps($array03); echo "------------------------------
"; ?>