Merge pull request #4019 from wlmb/challenges

Add solutions to PWC 111

4 files changed, 79 insertions, 0 deletions

diff --git a/challenge-111/wlmb/blog.txt b/challenge-111/wlmb/blog.txt
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+++ b/challenge-111/wlmb/blog.txt
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+https://wlmb.github.io/2021/05/03/PWC111/
diff --git a/challenge-111/wlmb/perl/ch-1.pl b/challenge-111/wlmb/perl/ch-1.pl
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+++ b/challenge-111/wlmb/perl/ch-1.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 111
+# Task 1: Search matrix
+#
+# See https://wlmb.github.io/2021/05/03/PWC111/#task-1-search-matrix
+use strict;
+use warnings;
+use v5.12;
+use POSIX qw(floor);
+# Input matrix from STDIN (not ARGV) as space and newline separated columns and rows.
+# Assume it is ordered as stated above
+my @elements= map {chomp; (split ' ')} <STDIN>; # no need for organizing in rows
+say "Input: $_ Output: ", binary_search($_, @elements) foreach @ARGV;
+
+sub binary_search { # binary search an ordered list
+    my $number=shift @_;
+    my @array=@_;
+    return 0 if $number<$array[0] or $number > $array[-1]; # trivial case
+    my $low=0;
+    my $high=@array; #beyond highest number
+    while($low<$high){
+	my $mid=floor(($low+$high)/2);
+	return 1     if $array[$mid]==$number;
+	return 0     if $mid==$low;
+	$low=$mid    if $number > $array[$mid];
+	$high=$mid   if $number < $array[$mid];
+    }
+    return 0;
+}
diff --git a/challenge-111/wlmb/perl/ch-2.pl b/challenge-111/wlmb/perl/ch-2.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 111
+# Task 2: Ordered letters
+#
+# See https://wlmb.github.io/2021/05/03/PWC111/#task-2-ordered-letters
+use strict;
+use warnings;
+use v5.12;
+use List::Util qw(all);
+my $word='';
+my $max_length=0;
+foreach(<>){
+    chomp;
+    $_=lc $_;
+    next unless m/^\w+$/; #Only allow word letters
+    next unless length>$max_length;
+    next unless sorted($_);
+    $word=$_;
+    $max_length=length;
+}
+say "\nword: $word length:\t$max_length";
+
+sub sorted {
+    my @chars=split '', shift;
+    return all {$chars[$_] le $chars[$_+1]} 0..$#chars-1;
+}
diff --git a/challenge-111/wlmb/perl/ch-2a.pl b/challenge-111/wlmb/perl/ch-2a.pl
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+#!/usr/bin/env perl
+# Perl weekly challenge 111
+# Task 2: Ordered letters
+#
+# See https://wlmb.github.io/2021/05/03/PWC111/#task-2-ordered-letters
+use strict;
+use warnings;
+use v5.12;
+use List::Util qw(all);
+my $length=shift @ARGV;
+foreach(<>){
+    chomp;
+    $_=lc $_;
+    next unless m/^\w+$/; #Only allow word letters
+    next unless length==$length;
+    next unless sorted($_);
+    say $_;
+}
+
+sub sorted {
+    my @chars=split '', shift;
+    return all {$chars[$_] le $chars[$_+1]} 0..$#chars-1;
+}