From f1831f1d20aaf1f1fcabfb66983550731913c6dd Mon Sep 17 00:00:00 2001
From: E7-87-83 <fungcheokyin@gmail.com>
Date: Sun, 16 May 2021 13:33:06 +0800
Subject: 2 Perl scripts, blogpost

---
 challenge-112/cheok-yin-fung/blog.txt     |  1 +
 challenge-112/cheok-yin-fung/perl/ch-1.pl | 23 +++++++++++++++++++++
 challenge-112/cheok-yin-fung/perl/ch-2.pl | 34 +++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)
 create mode 100644 challenge-112/cheok-yin-fung/blog.txt
 create mode 100644 challenge-112/cheok-yin-fung/perl/ch-1.pl
 create mode 100644 challenge-112/cheok-yin-fung/perl/ch-2.pl

diff --git a/challenge-112/cheok-yin-fung/blog.txt b/challenge-112/cheok-yin-fung/blog.txt
new file mode 100644
index 0000000000..a0a6007fb0
--- /dev/null
+++ b/challenge-112/cheok-yin-fung/blog.txt
@@ -0,0 +1 @@
+https://e7-87-83.github.io/coding/challenge_112.html
diff --git a/challenge-112/cheok-yin-fung/perl/ch-1.pl b/challenge-112/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..3156d06727
--- /dev/null
+++ b/challenge-112/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/perl
+# The Weekly Challenge 112
+# Task 1 Canonical Path
+use strict;
+use warnings;
+
+my $origin = $ARGV[0] || "/a//b/c/../../";
+
+my @directories = grep { $_ ne "" && $_ ne "."  } split "/", $origin;
+
+my @new_dirs = ();
+
+for (@directories) {
+    if ($_ ne "..") {
+        push @new_dirs, $_;
+    }
+    else {
+        pop @new_dirs;
+    }
+}
+
+print ( "/" . (join "/", @new_dirs));
+print "\n";
diff --git a/challenge-112/cheok-yin-fung/perl/ch-2.pl b/challenge-112/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..451a2aaa73
--- /dev/null
+++ b/challenge-112/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,34 @@
+#!/usr/bin/perl
+# The Weekly Challenge 112
+# Task 2 Climb Stairs
+use strict;
+use warnings;
+use Algorithm::Combinatorics qw /combinations/;
+
+my $n = $ARGV[0] || 5;
+
+if ($n <= 1) {
+    print "For one step to climb, there is only one option: \n1\n";
+} else {
+
+# ================== BEGIN: MAIN BODY OF THE SCRIPT =========
+my @all;
+
+for my $i ($n%2+$n/2 .. $n-1) {
+    my $iter = combinations([0..$i-1] , ($n-$i) );
+    my $str = "1" x $i;
+    while (my $c = $iter->next) {
+        my $str_clone = $str;
+        substr($str_clone, $_, 1) = "2" for (@{$c});
+        push @all, $str_clone;
+    }
+}
+
+push @all , "1" x $n;
+print "For $n steps to climb, the number of options is ", scalar @all, ":\n";
+print join "\n", @all;
+print "\n";
+
+# ==================== END: MAIN BODY OF THE SCRIPT =========
+
+}
-- 
cgit