Merge pull request #7288 from wlmb/challenges

Solve PWC196

3 files changed, 45 insertions, 0 deletions

diff --git a/challenge-196/wlmb/blog.txt b/challenge-196/wlmb/blog.txt
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+++ b/challenge-196/wlmb/blog.txt
@@ -0,0 +1 @@
+https://wlmb.github.io/2022/12/19/PWC196/
diff --git a/challenge-196/wlmb/perl/ch-1.pl b/challenge-196/wlmb/perl/ch-1.pl
new file mode 100755
index 0000000000..f6862e7826
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+++ b/challenge-196/wlmb/perl/ch-1.pl
@@ -0,0 +1,16 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 196
+# Task 1:  Pattern 132
+#
+# See https://wlmb.github.io/2022/12/19/PWC196/#task-1-pattern-132
+use v5.36;
+use Algorithm::Combinatorics qw(combinations);
+say(<<"FIN"), exit unless @ARGV && @ARGV>=3;
+Usage: $0 N1 N2 N3 [N4...]
+to find the first 132 pattern in the sequence N1 N2...
+FIN
+my $c=combinations(\@ARGV, 3);
+while(my $n=$c->next){
+    say(join " ", @ARGV, "->", @$n), exit if $n->[0]<$n->[2]<$n->[1];
+}
+say join " ", @ARGV, "->";
diff --git a/challenge-196/wlmb/perl/ch-2.pl b/challenge-196/wlmb/perl/ch-2.pl
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+++ b/challenge-196/wlmb/perl/ch-2.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+# Perl weekly challenge 196
+# Task 2:  Range List
+#
+# See https://wlmb.github.io/2022/12/19/PWC196/#task-2-range-list
+use v5.36;
+use List::Util qw(all pairmap);
+
+say(<<"FIN"), exit unless @ARGV > 0;
+Usage: $0 N1 [N2...]
+to identify subsequences of contiguous intgers
+FIN
+say("Expected integer arguments"), exit unless all {/^[+-]?\d+$/} @ARGV;
+my @input=my @rest=sort {$a <=> $b} @ARGV; # make sure list is sorted and make copies
+my $previous=my $first=shift @rest;
+say join " ", @input, "->",
+    pairmap {"[$a, $b]"}
+    map{subseq($_)} @rest, undef; # finish inputs with undef
+
+sub subseq($current){ # identify and output complete contiguous subsequences
+    my @output = $first<$previous ? ($first, $previous): ();
+    return @output if
+        !defined $current      # input is consumed
+	&& $first < $previous; # and a range has been found
+    $previous = $current, return () if $current==$previous+1; # not done yet
+    $first=$previous=$current; # prepare next sequence
+    return @output;
+}