Merge pull request #5311 from wlmb/challenges

Solve PWC141

3 files changed, 46 insertions, 0 deletions

diff --git a/challenge-141/wlmb/blog.txt b/challenge-141/wlmb/blog.txt
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+++ b/challenge-141/wlmb/blog.txt
@@ -0,0 +1 @@
+https://wlmb.github.io/2021/11/29/PWC141/
diff --git a/challenge-141/wlmb/perl/ch-1.pl b/challenge-141/wlmb/perl/ch-1.pl
new file mode 100755
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+++ b/challenge-141/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 141
+# Task 1: Number divisors
+#
+# See https://wlmb.github.io/2021/11/29/PWC141/#task-1-number-divisors
+use v5.12;
+use warnings;
+use PDL;
+use PDL::NiceSlice;
+#Set defaults and params. from com. line
+my %params=(try=>100, divisors=>8, results=>10, @ARGV);
+my ($try, $divisors, $results)
+    =@params{qw(try divisors results)};
+my $cells=zeroes $try;
+# count divisors for each number
+$cells($_:-1:$_)+=1 for(1..$try-1);
+# find all d-multiples
+my $multiples=$cells->xvals->where($cells==$divisors);
+die "Need to increase try" unless $multiples->nelem>=$results;
+my $out=$multiples(0:$results-1);
+say "try=$try, divisors=$divisors, results=$results, out=$out";
diff --git a/challenge-141/wlmb/perl/ch-2.pl b/challenge-141/wlmb/perl/ch-2.pl
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index 0000000000..03f3c416e1
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+++ b/challenge-141/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 141
+# Task 2: Like numbers
+#
+# See https://wlmb.github.io/2021/11/29/PWC141/#task-2-like-numbers
+use v5.12;
+use warnings;
+use PDL;
+use PDL::NiceSlice;
+
+die "Usage: ./ch-2.pl m n" unless @ARGV==2;
+my ($m,$n)=@ARGV;
+my $l=length $m;
+my $digits=pdl[split "", $m];
+my $multiples= pdl [
+    sort {$a<=>$b}
+         grep {$_!~/^0/&&$_%$n==0}
+         map {
+	     my $bits=pdl([split "", sprintf "%b", $_]);
+	     join "", $digits->where($bits->(-1:0))->list;
+    } 1..2**$l-2
+    ];
+say "m=$m, n=$n, Out=", $multiples->nelem,
+    "\nas multiples=$multiples";