Merge pull request #12018 from wlmb/challenges

Solve PWC321

3 files changed, 38 insertions, 0 deletions

diff --git a/challenge-321/wlmb/blog.txt b/challenge-321/wlmb/blog.txt
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+https://wlmb.github.io/2025/05/12/PWC321/
diff --git a/challenge-321/wlmb/perl/ch-1.pl b/challenge-321/wlmb/perl/ch-1.pl
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+++ b/challenge-321/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 321
+# Task 1:  Distinct Average
+#
+# See https://wlmb.github.io/2025/05/12/PWC321/#task-1-distinct-average
+use v5.36;
+use List::Util qw(uniq);
+my $N=@ARGV;
+die <<~"FIN" unless $N && $N%2==0;
+    Usage: $0 N1 N2...N2n
+    to remove the smallest and largest value of the list, average them and
+    count the distinct values produced.
+    FIN
+my @sorted = sort {$a <=> $b} @ARGV;
+my $N2 = $N/2-1; #
+say "@ARGV -> ", scalar uniq map {$sorted[$_]+$sorted[-1-$_]} 0..$N2;
diff --git a/challenge-321/wlmb/perl/ch-2.pl b/challenge-321/wlmb/perl/ch-2.pl
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+++ b/challenge-321/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 321
+# Task 2:  Backspace Compare
+#
+# See https://wlmb.github.io/2025/05/12/PWC321/#task-2-backspace-compare
+use v5.36;
+die <<~"FIN" unless @ARGV && @ARGV%2==0;
+    Usage: $0 A1 B1 A2 B2...
+    to find if strings An Bn are equal after all \#'s are
+    interpreted as backspace and applied to delete the preceding
+    character.
+    FIN
+for my($x, $y)(@ARGV){
+    my ($x_edited, $y_edited) = ($x, $y);   # make a copy
+    ($x_edited, $y_edited) = map {
+        1 while s/(^|[^\#])\#//g;           # apply backspaces. Deal with # at beginning
+        $_;                                 # return edited string
+    } ($x_edited, $y_edited);
+    my $result = $x_edited eq $y_edited? "True" : "False";
+    say "$x $y -> $result";
+}