TWC301

Challenge Link

Task1

We can find the largest number that can be formed from an array of numbers by sorting the string representation of those numbers:

#!/usr/bin/env perl
use strict;
use warnings;

sub largest_number{
  join '',sort {$b.$a <=> $a.$b} @{$_[0]}
}

printf "%s\n",largest_number([20,3]);
printf "%s\n",largest_number([3,30,34,5,9]);

Task2

We find the hamming distance of all the combinations of numbers and sum them:

#!/usr/bin/env perl
use strict;
use warnings;
use Algorithm::Combinatorics qw(combinations);
use List::Util qw(sum0);

sub hamming_distance{
  sum0 map {sum0 split '',sprintf "%b",$_->[0] ^ $_->[1]}
    combinations($_[0],2)
}

printf "%d\n",hamming_distance([4,14,2]);
printf "%d\n",hamming_distance([4,14,4]);