TWC332

Challenge Link

Task1

We convert each number into binary and join them with dashes:

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

sub binary_date{
  $_[0] =~ s/(\d+)/{sprintf "%b",$1}/rge
}

printf "%s\n",binary_date('2025-07-26');
printf "%s\n",binary_date('2000-02-02');
printf "%s\n",binary_date('2024-12-31');

Task2

We check if each letters occurred odd number of times:

#!/usr/bin/env perl
use strict;
use warnings;
use List::Util qw(all);

sub odd_letters{
  my %h;
  $h{$_}++ foreach split '',$_[0];
  all{$h{$_} & 1} keys %h
}

printf "%d\n",odd_letters('weekly');
printf "%d\n",odd_letters('perl');
printf "%d\n",odd_letters('challenge');

TWC331

Challenge Link

Task1

We return length of the last word in the string:

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

sub last_word{
  length((split /\s/,$_[0])[-1])
}

printf "%d\n",last_word('The Weekly Challenge');
printf "%d\n",last_word('    Hello World    ');
printf "%d\n",last_word('Let\'s begin the fun');

Task2

We check if the strings are of the same length and only differ in one position:

#!/usr/bin/env perl
use strict;
use warnings;
use List::MoreUtils qw(uniq pairwise);

sub buddy_strings{
  return 0 if length($_[0]) != length($_[1]);
  my @s1 = split '',$_[0];
  return 1 if $_[0] eq $_[1] and @s1 > uniq(@s1);
  my @s2 = split '',$_[1];
  return 0 if (join('',sort @s1) ne join('',sort @s2));
  (grep{$_ != 0} (pairwise{$a cmp $b} @s1,@s2)) == 2
}

printf "%d\n",buddy_strings('fuck','fcuk');
printf "%d\n",buddy_strings('love','love');
printf "%d\n",buddy_strings('fodo','food');
printf "%d\n",buddy_strings('feed','feed');

TWC330

Challenge Link

Task1

We keep on clearing adjacent letter and digit pairs:

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

sub clear_digits{
  my ($str) = @_;
  1 while($str =~ s/\D\d//);
  $str
}

printf "%s\n",clear_digits('cab12');
printf "%s\n",clear_digits('xy99');
printf "%s\n",clear_digits('pa1erl');

Task2

We make each word lowercase if its length is less than 3, otherwise make it titlecase:

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

sub title_capital{
  join ' ',map{length($_) < 3 ? lc : ucfirst lc} split ' ',$_[0];
}

printf "%s\n",title_capital('PERL IS gREAT');
printf "%s\n",title_capital('THE weekly challenge');
printf "%s\n",title_capital('YoU ARE A stAR');

TWC329

Challenge Link

Task1

We extract the unique numbers:

#!/usr/bin/env perl
use strict;
use warnings;
use Data::Show;
use List::Util qw(uniq);

sub counter_integers{
  uniq $_[0] =~ /(\d+)/g
}

print show counter_integers('the1weekly2challenge2');
print show counter_integers('go21od1lu5c7k');
print show counter_integers('4p3e2r1l');

Task2

We find letters which appear both in lower and upper case:

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

sub nice_string{
  my ($str) = @_;
  my %h;
  $h{lc $_} |= 1 + /[a-z]/ foreach split '',$str;
  foreach my $c(keys %h){
    next if $h{$c} == 3;
    $str =~ s/$c//gi;
  }
  $str
}

printf "%s\n",nice_string('YaaAho');
printf "%s\n",nice_string('cC');
printf "%s\n",nice_string('A');