####################################################################
##                               MAIN
####################################################################

my @array = (1, 4, 4, 65, 100, 102);

my $closest_element = @{closest_element(\@array)}[0];

print "The closest element to the element $element in the array (@array) is the element $closest_element\n";

####################################################################
##                               SUBS
####################################################################

sub closest_element { #to execute a binary search on the closest element of an input array
  
  my ($array) = @_;  
  
  my $end = @$array;
  
  my $not_middle = int(($end-1) / 2); #compute $not_middle
  
  my $try = @$array[$not_middle]; #try an element
  
  return $try <= $element ? #return the closest element after having checked the below statements
    
    (abs($try-$element)<abs(@$array[$not_middle+1]-$element) ? 
     
     [$try]
     
     :
     
     $element <= @$array[$not_middle+1] ?
     
     [@$array[$not_middle+1]]
     
     :
     
     closest_element([@$array[$not_middle+1 .. $end-1]]))
    
    :
    
    (abs($try-$element)<abs(@$array[$not_middle-1]-$element) ?
     
     [$try] 
     
     : 
     
     $element >= @$array[$not_middle-1] ?
     
     [@$array[$not_middle-1]] 
     
     : 
     
     closest_element([@$array[0 .. $not_middle]]));
  
}