Merge pull request #9256 from wlmb/challenges

Solve PWC248

3 files changed, 32 insertions, 0 deletions

diff --git a/challenge-248/wlmb/blog.txt b/challenge-248/wlmb/blog.txt
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+https://wlmb.github.io/2023/12/17/PWC248/
diff --git a/challenge-248/wlmb/perl/ch-1.pl b/challenge-248/wlmb/perl/ch-1.pl
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+++ b/challenge-248/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 248
+# Task 1:  Shortest Distance
+#
+# See https://wlmb.github.io/2023/12/17/PWC248/#task-1-shortest-distance
+use v5.36;
+use PDL;
+die <<~"FIN" unless @ARGV==2;
+    Usage: $0 string letter
+    to obtain the shortest distances.
+    FIN
+my @letters=split "", $ARGV[0];
+my $i=pdl(grep {$letters[$_] eq $ARGV[1]} 0..@letters-1);
+my $j=sequence(0+@letters);
+say "@ARGV; $ARGV[1] -> ", ($i->dummy(1)-$j->dummy(0))->abs->minover;
diff --git a/challenge-248/wlmb/perl/ch-2.pl b/challenge-248/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 248
+# Task 2:  Submatrix Sum
+#
+# See https://wlmb.github.io/2023/12/17/PWC248/#task-2-submatrix-sum
+use v5.36;
+use PDL;
+use PDL::NiceSlice;
+die <<~"FIN" unless @ARGV==1;
+    Usage: $0 M
+    to sum 2x2 the overlapped submatrices of matrix M
+    FIN
+my $m=pdl(shift);
+my $n=pdl($m(0:-2,0:-2),$m(1:-1,0:-2),$m(0:-2,1:-1),$m(1:-1,1:-1))
+    ->mv(-1,0)->sumover;
+say "$m->$n"