Merge pull request #11560 from wlmb/challenges

Solve PWC308

3 files changed, 31 insertions, 0 deletions

diff --git a/challenge-308/wlmb/blog.txt b/challenge-308/wlmb/blog.txt
new file mode 100644
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+++ b/challenge-308/wlmb/blog.txt
@@ -0,0 +1 @@
+https://wlmb.github.io/2025/02/10/PWC308/
diff --git a/challenge-308/wlmb/perl/ch-1.pl b/challenge-308/wlmb/perl/ch-1.pl
new file mode 100755
index 0000000000..52948bcf89
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+++ b/challenge-308/wlmb/perl/ch-1.pl
@@ -0,0 +1,16 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 308
+# Task 1:  Count Common
+#
+# See https://wlmb.github.io/2025/02/10/PWC308/#task-1-count-common
+use v5.36;
+die <<~"FIN" unless  @ARGV==2;
+    Usage $0 S1 S2
+    to find how many words are common to the
+    space separated strings S1 and S2
+    FIN
+my @seen;
+for my $x(0,1){
+    ++$seen[$x]{$_}for split" ",$ARGV[$x];
+}
+say "s1 = $ARGV[0], s2=$ARGV[1] -> ", 0+grep{$seen[0]{$_}} keys %{$seen[1]};
diff --git a/challenge-308/wlmb/perl/ch-2.pl b/challenge-308/wlmb/perl/ch-2.pl
new file mode 100755
index 0000000000..2e21f0b9dd
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+++ b/challenge-308/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 308
+# Task 2:  Decode XOR
+#
+# See https://wlmb.github.io/2025/02/10/PWC308/#task-2-decode-xor
+use v5.36;
+die <<~"FIN" unless @ARGV;
+    Usage: $0 I E_0 E_1...E_n
+    to decode the sequence  E_j=Oj^O_{j+1} and find the original sequence
+    O_j, j=0..n+1 given its starting value I
+    FIN
+push my @original, my $initial=shift;
+push @original, $original[-1]^$_ for @ARGV;
+say "initial=$initial, encoded=@ARGV -> @original"