rjt's Week 341 solutions, blog, and tests

challenge-341/ryan-thompson/README.md

@@ -1,19 +1,18 @@
 # Ryan Thompson
 
-## Week 301 Solutions
+## Week 341 Solutions
 
-### Task 1 › Largest Number
+### Task 1 › Broken Keyboard
 
  * [Perl](perl/ch-1.pl)
 
-### Task 2 › Hamming Distance
+### Task 2 › Reverse Prefix
 
  * [Perl](perl/ch-2.pl)
- * [C](c/ch-2.c)
 
 ## Blog
 
- * [Hamming Distance and Large Numbers](https://ry.ca/2024/12/pwc-301-hamming-distance-and-large-numbers/)
+ * [Brken Keybard and Reverse Prefix](https://ry.ca/2025/10/brken-keybards-reverse-prefixes/)
 
 ## Tests
 

challenge-341/ryan-thompson/blog.txt

@@ -0,0 +1 @@
+https://ry.ca/2025/10/brken-keybards-reverse-prefixes/

challenge-341/ryan-thompson/perl/ch-1.pl

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+#!/usr/bin/env perl
+
+use v5.38;
+
+# Upper/lowercase are usually on the same key, thus we ignore case
+sub apssible { grep !/[@_\0]/i, split /\s+/, shift }
+sub pssible {
+    #my $re = qr/[@_\0]/i;
+    #say STDERR $re;
+    grep !/[@_\0]/i, split /\s+/, shift 
+}
+
+say join ' ', pssible(shift, @ARGV) if @ARGV

challenge-341/ryan-thompson/perl/ch-2.pl

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+#!/usr/bin/env perl
+
+use v5.38;
+
+sub rev_prefix { $_[0] =~ s/^(.+?\Q$_[1]\E)/reverse $1/er }
+
+say rev_prefix(@ARGV) if @ARGV == 2;

challenge-341/ryan-thompson/perl/t/ch-1.t

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+#!perl
+
+require './ch-1.pl';
+
+use Test2::V0;
+
+# Scalar (count)
+is  pssible('Hello world',               'd'     ), 1;
+is  pssible('apple banana cherry',       'a', 'e'), 0;
+is  pssible('Coding is fun',             ()      ), 3;
+is  pssible('The Weekly Challenge',      'a', 'b'), 2;
+is  pssible('Perl and Python',           'p'     ), 1;
+
+# Array
+is [pssible('Hello world',               'd'     )], ['Hello'];
+is [pssible('Foo bar baz',               'z'     )], ['Foo', 'bar'];
+is [pssible('All words impossible',      'l', 'd')], [ ];
+
+# Degenerate
+is  pssible(''),   0;
+is [pssible('')], [ ];
+
+# hack3r! but not really.
+ok dies { pssible('foo', 'a](?{ warn })[') };
+
+done_testing;

challenge-341/ryan-thompson/perl/t/ch-2.t

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+#!perl
+
+require './ch-2.pl';
+
+use Test2::V0;
+
+is rev_prefix(programming   => 'g'), 'gorpramming';
+is rev_prefix(hello         => 'h'), 'hello',
+is rev_prefix(abcdefghij    => 'h'), 'hgfedcbaij';
+is rev_prefix(reverse       => 's'), 'srevere';
+is rev_prefix(perl          => 'r'), 'repl';
+
+is rev_prefix('', ''), '';
+is rev_prefix('a','a'), 'a';
+
+# hack3r?
+ok lives { rev_prefix('test', qr/(?{ die "u got pwned" })/) };
+
+done_testing;