Solve PWC212

3 files changed, 68 insertions, 0 deletions

diff --git a/challenge-212/wlmb/blog.txt b/challenge-212/wlmb/blog.txt
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+https://wlmb.github.io/2023/04/10/PWC212/
+
diff --git a/challenge-212/wlmb/perl/ch-1.pl b/challenge-212/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 212
+# Task 1:  Jumping Letters
+#
+# See https://wlmb.github.io/2023/04/10/PWC212/#task-1-jumping-letters
+use v5.36;
+
+die <<~"FIN" unless @ARGV;
+    Usage: $0 word J1 [J2...]
+    Replace word after jumping its first J1 positions, its second letter
+    J2  positions and so on.
+    FIN
+
+my @letters="a".."z";
+my %index_of;
+my $counter=0;
+$index_of{$_}=$counter++ for @letters;
+
+my @input=split "", my $input=shift;
+my @jumps=@ARGV;
+die "Expected as many jumps as letters" unless @input==@jumps;
+my @output=
+    map {
+	my $output=$letters[($index_of{lc $input[$_]}+$jumps[$_])%@letters];
+	$input[$_]=~/[A-Z]/?uc $output:$output
+    } 0..@input-1;
+my $output = join "", @output;
+say "$input -> $output";
diff --git a/challenge-212/wlmb/perl/ch-2.pl b/challenge-212/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 212
+# Task 2:  Rearrange Groups
+#
+# See https://wlmb.github.io/2023/04/10/PWC212/#task-2-rearrange-groups
+use v5.36;
+
+die <<~"FIN" unless @ARGV;
+    Usage: $0 S N1 [N2...]
+    to split the set N1 N2... into consecutive groups of size S
+    FIN
+
+my $size=shift;
+my @ordered=sort {$a <=> $b} @ARGV;
+my @groups;
+my $success=1;
+while(@ordered){
+    my $group=next_group();
+    $success=0, last unless defined $group;
+    push @groups, $group;
+}
+say "Input: @ARGV, size: $size";
+say "Output: -1" unless $success;
+say "Output: (", join(")(", map {join ", ", @$_} @groups), ")" if $success;
+
+sub next_group(){
+    my @group;
+    my @repeated;
+    while(@ordered && @group < $size){
+	my $x=shift @ordered;
+	push(@repeated, $x), next if @group and $group[-1]==$x;
+	return if @group and $group[-1]+1 != $x;
+	push @group, $x;
+    }
+    @ordered=(@repeated, @ordered);
+    return [@group] if @group==$size;
+    return;
+}