Merge pull request #6965 from wlmb/challenges

Solve PWC 188

3 files changed, 44 insertions, 0 deletions

diff --git a/challenge-188/wlmb/blog.txt b/challenge-188/wlmb/blog.txt
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+++ b/challenge-188/wlmb/blog.txt
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+https://wlmb.github.io//2022/10/25/PWC188.org
diff --git a/challenge-188/wlmb/perl/ch-1.pl b/challenge-188/wlmb/perl/ch-1.pl
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+++ b/challenge-188/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 188
+# Task 1:  Divisible Pairs
+#
+# See https://wlmb.github.io/2022/10/25/PWC188/#task-1-divisible-pairs
+use v5.36;
+use Algorithm::Combinatorics qw(combinations);
+die <<EOF unless @ARGV>=3;
+Usage: $0 D N1 N2 [N3...]\nto count distinct ordered pairs of integers Ni
+that add to a multiple of D
+EOF
+my $divisor=shift;
+my @list=sort @ARGV;
+my $iter=combinations(\@list, 2);
+my $count=0;
+while(my $z=$iter->next){
+    my ($x, $y)=@$z;
+    ++$count if ($x+$y)%$divisor==0;
+}
+say "The number of pairs from the list ",
+    join(", ", @ARGV), " with sum divisible by $divisor is $count";
diff --git a/challenge-188/wlmb/perl/ch-2.pl b/challenge-188/wlmb/perl/ch-2.pl
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+++ b/challenge-188/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 188
+# Task 2:  Total Zero
+#
+# See https://wlmb.github.io/2022/10/25/PWC188/#task-2-total-zero
+use v5.36;
+use POSIX qw(floor);
+die <<EOF unless @ARGV==2;
+Usage: $0 x y
+To count operations required to bring x or y to zero by succesive subtraction.
+EOF
+my ($counter, $actual)=(0, 0);
+my ($x, $y)=my($x0, $y0)=@ARGV;
+die "Only positive integers allowed" unless $x>0 and $y>0 and $x==floor $x and $y==floor $y;
+use integer;
+while($y>0){
+    my ($d, $r)=($x/$y, $x%$y);
+    $counter += $d;
+    ++$actual;
+    ($x, $y)=($y, $r);
+}
+say "The number of operations required to bring $x0 $y0 to zero is $counter (divisions: $actual)";