Array Median

We are given two sorted arrays, our task is to merge them and return the median. Let’s start with the naive approach: just let Perl sort the list and select the median.

#!/usr/bin/perl
use warnings;
use strict;
use experimental qw( signatures );

sub array_median_naive($arr1, $arr2) {
    my @m = sort { $a <=> $b } @$arr1, @$arr2;
    return unless @m;

    return @m % 2 ? $m[ $#m / 2 ]
                  : ($m[ $#m / 2 ] + $m[ @m / 2 ]) / 2
}