From 2a05f98302637a957d242511fb4ef94db4c6b716 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 13:29:20 +0100
Subject: Given examples

---
 challenge-096/abigail/t/ctest.ini      | 7 +++++++
 challenge-096/abigail/t/input-1-1      | 2 ++
 challenge-096/abigail/t/input-2-1      | 2 ++
 challenge-096/abigail/t/output-1-1.exp | 2 ++
 challenge-096/abigail/t/output-2-1.exp | 2 ++
 5 files changed, 15 insertions(+)
 create mode 100644 challenge-096/abigail/t/ctest.ini
 create mode 100644 challenge-096/abigail/t/input-1-1
 create mode 100644 challenge-096/abigail/t/input-2-1
 create mode 100644 challenge-096/abigail/t/output-1-1.exp
 create mode 100644 challenge-096/abigail/t/output-2-1.exp

diff --git a/challenge-096/abigail/t/ctest.ini b/challenge-096/abigail/t/ctest.ini
new file mode 100644
index 0000000000..1e78d5aadc
--- /dev/null
+++ b/challenge-096/abigail/t/ctest.ini
@@ -0,0 +1,7 @@
+[names]
+1-1 = Given examples
+2-1 = Given examples
+
+
+[1-1]
+trim = 0
diff --git a/challenge-096/abigail/t/input-1-1 b/challenge-096/abigail/t/input-1-1
new file mode 100644
index 0000000000..ed78ab1367
--- /dev/null
+++ b/challenge-096/abigail/t/input-1-1
@@ -0,0 +1,2 @@
+The Weekly Challenge
+    Perl and   Raku are  part of the same family  
diff --git a/challenge-096/abigail/t/input-2-1 b/challenge-096/abigail/t/input-2-1
new file mode 100644
index 0000000000..cdfe0772e5
--- /dev/null
+++ b/challenge-096/abigail/t/input-2-1
@@ -0,0 +1,2 @@
+kitten sitting
+sunday monday
diff --git a/challenge-096/abigail/t/output-1-1.exp b/challenge-096/abigail/t/output-1-1.exp
new file mode 100644
index 0000000000..a551829850
--- /dev/null
+++ b/challenge-096/abigail/t/output-1-1.exp
@@ -0,0 +1,2 @@
+Challenge Weekly The
+family same the of part are Raku and Perl
diff --git a/challenge-096/abigail/t/output-2-1.exp b/challenge-096/abigail/t/output-2-1.exp
new file mode 100644
index 0000000000..f1e5eeed2d
--- /dev/null
+++ b/challenge-096/abigail/t/output-2-1.exp
@@ -0,0 +1,2 @@
+3
+2
-- 
cgit 


From ace53ffec67794fec91f402c89dbb1f4d2c42bf8 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 13:58:22 +0100
Subject: Perl solution for week 96/part 1

---
 challenge-096/abigail/perl/ch-1.pl | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 challenge-096/abigail/perl/ch-1.pl

diff --git a/challenge-096/abigail/perl/ch-1.pl b/challenge-096/abigail/perl/ch-1.pl
new file mode 100644
index 0000000000..ddca656054
--- /dev/null
+++ b/challenge-096/abigail/perl/ch-1.pl
@@ -0,0 +1,33 @@
+#!/opt/perl/bin/perl
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+#
+# For the challenge description, see ../README.md
+#
+
+#
+# The challenge doesn't describe what a word is, or what to
+# do with things which are neither words, nor whitespace, like
+# punctuation.
+#
+# For instance, what should happen to the sentence:
+#
+#     "The Weekly Challenge, Part 1!"
+#
+# So, we're using the easy way out, and assume anything which isn't
+# whitespace to be part of a word. After all, the examples assumen
+# all the world is ASCII letters and spaces.
+#
+# Which makes the excercise too trivial to be called a challenge.
+#
+
+# Extract 'words', reverse the list, and print it.
+say join " " => reverse /\S+/g for <>;
-- 
cgit 


From 4f87b77d36d715e794302abb707da11eb736ba58 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 14:21:13 +0100
Subject: AWK and Node.js solutions for week 96, part 1

---
 challenge-096/abigail/README.md    | 68 ++++++++++++++++++--------------------
 challenge-096/abigail/awk/ch-1.awk | 10 ++++++
 challenge-096/abigail/node/ch-1.js | 15 +++++++++
 3 files changed, 58 insertions(+), 35 deletions(-)
 create mode 100644 challenge-096/abigail/awk/ch-1.awk
 create mode 100644 challenge-096/abigail/node/ch-1.js

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index a82f466a38..60888652f5 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -1,62 +1,60 @@
 # Solution by Abigail
 
-## [Task 1](https://perlweeklychallenge.org/blog/perl-weekly-challenge-095/#TASK1): 
+## [Reverse Words](https://perlweeklychallenge.org/blog/perl-weekly-challenge-096/#TASK1)
 
-You are given a number `$N`.
+You are given a string `$S`.
 
-Write a script to figure out if the given number is Palindrome.
-Print `1` if true otherwise `0`.
+Write a script to reverse the order of words in the given string.
+The string may contain leading/trailing spaces. The string may have
+more than one space between words in the string. Print the result
+without leading/trailing spaces and there should be only one space
+between words.
 
 ### Examples
 ~~~~
-Input: 1221
-Output: 1
+Input: $S = "The Weekly Challenge"
+Output: "Challenge Weekly The"
 
-Input: -101
-Output: 0, since -101 and 101- are not the same.
-
-Input: 90
-Output: 0
+Input: $S = "    Perl and   Raku are  part of the same family  "
+Output: "family same the of part are Raku and Perl"
 ~~~~
 
 ### Solutions
-* [awk](awk/ch-1.c)
-* [C](c/ch-1.c)
-* [Node](node/ch-1.js)
+* [AWK](awk/ch-1.awk)
+* [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
-* [Python](python/ch-1.py)
 
 ### Blog
-[Perl Weekly Challenge 95, Part 1](https://wp.me/pcxd30-kq)
 
 
-## [Task 2](https://perlweeklychallenge.org/blog/perl-weekly-challenge-095/#TASK2)
+## [Edit Distance](https://perlweeklychallenge.org/blog/perl-weekly-challenge-096/#TASK2)
 
-Write a script to demonstrate `Stack` operations like below:
+You are given two strings `$S1` and `$S2`.
 
-* `push($n)` - add $n to the stack
-* `pop()` - remove the top element
-* `top()` - get the top element
-* `min()` - return the minimum element
+Write a script to find out the minimum operations required to convert
+`$S1` into `$S2`. The operations can be insert, remove or replace a
+character. Please check out [Wikipedia
+page](https://en.wikipedia.org/wiki/Edit_distance) for more information.
 
 ### Example
 ~~~~
-my $stack = Stack->new;
-$stack->push(2);
-$stack->push(-1);
-$stack->push(0);
-$stack->pop;       # removes 0
-print $stack->top; # prints -1
-$stack->push(0);
-print $stack->min; # prints -1
+Input: $S1 = "kitten"; $S2 = "sitting"
+Output: 3
+
+Operation 1: replace 'k' with 's'
+Operation 2: replace 'e' with 'i'
+Operation 3: insert 'g' at the end
+~~~~
+
+~~~~
+Input: $S1 = "sunday"; $S2 = "monday"
+Output: 2
+
+Operation 1: replace 's' with 'm'
+Operation 2: replace 'u' with 'o'
 ~~~~
 
 ### Solutions
-* [awk](awk/ch-2.awk)
-* [C](c/ch-2.c)
-* [Node](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
-* [Python](python/ch-2.py)
 
 ### Blog
-[Perl Weekly Challenge 95, Part 2](https://wp.me/pcxd30-ld)
diff --git a/challenge-096/abigail/awk/ch-1.awk b/challenge-096/abigail/awk/ch-1.awk
new file mode 100644
index 0000000000..744c154648
--- /dev/null
+++ b/challenge-096/abigail/awk/ch-1.awk
@@ -0,0 +1,10 @@
+#
+# AWK splits lines on whitespace, making each field available
+# in $1, $2, ..., etc. So, we just print the fields in reverse,
+# followed by a space (or a newline after the last/first).
+#
+{
+    for (i = NF; i; i --) {
+        printf "%s%s", $i, (i == 1 ? "\n" : " ");
+    }
+}
diff --git a/challenge-096/abigail/node/ch-1.js b/challenge-096/abigail/node/ch-1.js
new file mode 100644
index 0000000000..b31524a686
--- /dev/null
+++ b/challenge-096/abigail/node/ch-1.js
@@ -0,0 +1,15 @@
+//
+// Read STDIN. Split on newlines, filter out empty lines, then call "main".
+//
+  require      ("fs")
+. readFileSync (0)               // Read all.
+. toString     ()                // Turn it into a string.
+. split        ("\n")            // Split on newlines.
+. filter       (_ => _ . length) // Filter out empty lines.
+. map          (_ => console . log (_ . trim    ()        // Remove leading
+                                                          // and trailing
+                                                          // whitespace.
+                                      . split   (/\s+/)   // split ...
+                                      . reverse ()        // reverse ...
+                                      . join    (" ")))   // and recombine.
+;
-- 
cgit 


From b6b448564c1d62f1d4c623b9bce5f8a9f8d8b652 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 14:40:04 +0100
Subject: Python solution for week 95, part 1

---
 challenge-096/abigail/README.md      | 1 +
 challenge-096/abigail/python/ch-1.py | 6 ++++++
 2 files changed, 7 insertions(+)
 create mode 100644 challenge-096/abigail/python/ch-1.py

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index 60888652f5..c45d495eb6 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -23,6 +23,7 @@ Output: "family same the of part are Raku and Perl"
 * [AWK](awk/ch-1.awk)
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
+* [Python](python/ch-1.py)
 
 ### Blog
 
diff --git a/challenge-096/abigail/python/ch-1.py b/challenge-096/abigail/python/ch-1.py
new file mode 100644
index 0000000000..ddc34e2633
--- /dev/null
+++ b/challenge-096/abigail/python/ch-1.py
@@ -0,0 +1,6 @@
+import fileinput
+
+for line in fileinput . input ():
+    words = line . strip () . split ()
+    words . reverse ()
+    print (" " . join (words))
-- 
cgit 


From 6be85bd8cd6960a0fd063e67b78f88b39df528e9 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 15:10:35 +0100
Subject: C solution for week 96/part 1

---
 challenge-096/abigail/README.md |  1 +
 challenge-096/abigail/c/ch-1.c  | 66 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 challenge-096/abigail/c/ch-1.c

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index c45d495eb6..ee7bed56c2 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -20,6 +20,7 @@ Output: "family same the of part are Raku and Perl"
 ~~~~
 
 ### Solutions
+* [C](c/ch-1.c)
 * [AWK](awk/ch-1.awk)
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
diff --git a/challenge-096/abigail/c/ch-1.c b/challenge-096/abigail/c/ch-1.c
new file mode 100644
index 0000000000..22ebafd404
--- /dev/null
+++ b/challenge-096/abigail/c/ch-1.c
@@ -0,0 +1,66 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+# include <ctype.h>
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  strlen;
+
+    while ((strlen = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        size_t end = strlen;
+        size_t begin;
+        size_t output = 0;
+        while (end > 0) {
+            /*
+             * Skip tailing whitespace
+             */
+            while (end > 0 && isspace (line [end - 1])) {
+                end --;
+            }
+
+            /*
+             * 'end' now just after the end of a word, or
+             * at the beginning of the string; if the latter,
+             * there is nothing left to print.
+             */
+
+            if (end <= 0) {
+                break;
+            }
+
+            /*
+             * Find the beginning of a word
+             */
+            begin = end - 1;
+            while (begin > 0 && !isspace (line [begin - 1])) {
+                begin --;
+            }
+
+            /*
+             * Extract the word out of the string: allocate memory,
+             * and copy the right part of the input.
+             */
+            char * word;
+            if ((word = malloc ((end - begin + 1) * sizeof (char))) == NULL) {
+                fprintf (stderr, "Out of memory\n");
+                exit (1);
+            }
+            stpncpy (word, line + begin, end - begin);
+
+            /*
+             * Print the string, prepended (except the first printed word)
+             * by a space.
+             */
+            printf ("%s%s", output ++ ? " " : "", word);
+
+            end = begin;
+        }
+        printf ("\n");
+    }
+    free (line);
+
+    return (0);
+}
-- 
cgit 


From a1cee94025af8df9d613d8789839c208e453a914 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 16:35:53 +0100
Subject: Ruby solution for week 95/part 1

---
 challenge-096/abigail/README.md    | 1 +
 challenge-096/abigail/ruby/ch-1.rb | 3 +++
 2 files changed, 4 insertions(+)
 create mode 100644 challenge-096/abigail/ruby/ch-1.rb

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index ee7bed56c2..ea55819653 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -25,6 +25,7 @@ Output: "family same the of part are Raku and Perl"
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
 * [Python](python/ch-1.py)
+* [Ruby](ruby/ch-1.py)
 
 ### Blog
 
diff --git a/challenge-096/abigail/ruby/ch-1.rb b/challenge-096/abigail/ruby/ch-1.rb
new file mode 100644
index 0000000000..064f780345
--- /dev/null
+++ b/challenge-096/abigail/ruby/ch-1.rb
@@ -0,0 +1,3 @@
+ARGF . each_line do |_|
+    puts ((_ . split (/\s+/)) . grep (/\S/)) . reverse . join (" ")
+end
-- 
cgit 


From 4a2818e3550e3f914e285bc0bc67b10c61c24cf5 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 17:05:29 +0100
Subject: Perl solution for week 96, part 2

---
 challenge-096/abigail/perl/ch-2.pl | 46 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 challenge-096/abigail/perl/ch-2.pl

diff --git a/challenge-096/abigail/perl/ch-2.pl b/challenge-096/abigail/perl/ch-2.pl
new file mode 100644
index 0000000000..7fc41b2604
--- /dev/null
+++ b/challenge-096/abigail/perl/ch-2.pl
@@ -0,0 +1,46 @@
+
+
+use 5.032;
+
+use strict;
+use warnings;
+no  warnings 'syntax';
+
+use experimental 'signatures';
+use experimental 'lexical_subs';
+
+use List::Util 'min';
+
+#
+# This is an implementation of the Wagner Fischer algorithm, which
+# calculates the Levenshtein distance.
+#
+# See https://en.wikipedia.org/wiki/Wagner%E2%80%93Fischer_algorithm
+#
+sub LevenshteinDistance ($first, $second) {
+   ($first, $second) = ($second, $first) if length ($first) <
+                                            length ($second);
+    my $distance;
+    for (my $i = 0; $i <= length ($first); $i ++) {
+        for (my $j = 0; $j <= length ($second); $j ++) {
+            $$distance [$i] [$j] =
+                $j == 0 ? $i
+              : $i == 0 ? $j
+              : min ($$distance [$i - 1] [$j]     + 1,
+                     $$distance [$i]     [$j - 1] + 1,
+                     $$distance [$i - 1] [$j - 1] + 
+                        (substr ($first,  $i - 1, 1) eq
+                         substr ($second, $j - 1, 1) ? 0 : 1))
+        }
+        #
+        # We only need the previous row; this reduces the memory
+        # from O (N * M) to O (min (N, M)), where N and M are the
+        # lengths of the input strings.
+        #
+        undef $$distance [$i - 1] if $i;
+    }
+    $$distance [-1] [-1];
+}
+
+
+say LevenshteinDistance /\S+/g for <>;
-- 
cgit 


From 627ff2ed726fc3b15e0606b0570e10262a2553e6 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 17:31:57 +0100
Subject: Another example for part 2

---
 challenge-096/abigail/t/ctest.ini      | 1 +
 challenge-096/abigail/t/input-2-2      | 1 +
 challenge-096/abigail/t/output-2-2.exp | 1 +
 3 files changed, 3 insertions(+)
 create mode 100644 challenge-096/abigail/t/input-2-2
 create mode 100644 challenge-096/abigail/t/output-2-2.exp

diff --git a/challenge-096/abigail/t/ctest.ini b/challenge-096/abigail/t/ctest.ini
index 1e78d5aadc..99eb989ad5 100644
--- a/challenge-096/abigail/t/ctest.ini
+++ b/challenge-096/abigail/t/ctest.ini
@@ -1,6 +1,7 @@
 [names]
 1-1 = Given examples
 2-1 = Given examples
+2-2 = Wikipedia example
 
 
 [1-1]
diff --git a/challenge-096/abigail/t/input-2-2 b/challenge-096/abigail/t/input-2-2
new file mode 100644
index 0000000000..3575a4749f
--- /dev/null
+++ b/challenge-096/abigail/t/input-2-2
@@ -0,0 +1 @@
+sunday saturday
diff --git a/challenge-096/abigail/t/output-2-2.exp b/challenge-096/abigail/t/output-2-2.exp
new file mode 100644
index 0000000000..00750edc07
--- /dev/null
+++ b/challenge-096/abigail/t/output-2-2.exp
@@ -0,0 +1 @@
+3
-- 
cgit 


From 6987a3e81c21dbc1bda95ced9fc5e352a337f37e Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 17:57:25 +0100
Subject: Tiny optimization for perl solution for week 96, part 2

---
 challenge-096/abigail/perl/ch-2.pl | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/challenge-096/abigail/perl/ch-2.pl b/challenge-096/abigail/perl/ch-2.pl
index 7fc41b2604..bb58c84569 100644
--- a/challenge-096/abigail/perl/ch-2.pl
+++ b/challenge-096/abigail/perl/ch-2.pl
@@ -24,8 +24,7 @@ sub LevenshteinDistance ($first, $second) {
     for (my $i = 0; $i <= length ($first); $i ++) {
         for (my $j = 0; $j <= length ($second); $j ++) {
             $$distance [$i] [$j] =
-                $j == 0 ? $i
-              : $i == 0 ? $j
+                $i == 0 || $j == 0 ? $i + $j
               : min ($$distance [$i - 1] [$j]     + 1,
                      $$distance [$i]     [$j - 1] + 1,
                      $$distance [$i - 1] [$j - 1] + 
-- 
cgit 


From 7209da1bc64d0ad614b51fdaff8f188715d8f81d Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 18:10:38 +0100
Subject: Node solution for week 96, part 2

---
 challenge-096/abigail/README.md    |  1 +
 challenge-096/abigail/node/ch-2.js | 43 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 challenge-096/abigail/node/ch-2.js

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index ea55819653..b19e1c3934 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -58,6 +58,7 @@ Operation 2: replace 'u' with 'o'
 ~~~~
 
 ### Solutions
+* [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
 
 ### Blog
diff --git a/challenge-096/abigail/node/ch-2.js b/challenge-096/abigail/node/ch-2.js
new file mode 100644
index 0000000000..03f423b2ec
--- /dev/null
+++ b/challenge-096/abigail/node/ch-2.js
@@ -0,0 +1,43 @@
+//
+// Read STDIN. Split on newlines, filter out empty lines, then call "main".
+//
+  require      ("fs")
+. readFileSync (0)               // Read all.
+. toString     ()                // Turn it into a string.
+. split        ("\n")            // Split on newlines.
+. filter       (_ => _ . length) // Filter out empty lines.
+. map          (_ => console . log (LevenshteinDistance (_ . split (/\s+/))))
+;
+
+//
+// This is an implementation of the Wagner Fischer algorithm, which
+// calculates the Levenshtein distance.
+//
+// See https://en.wikipedia.org/wiki/Wagner%E2%80%93Fischer_algorithm
+//
+function LevenshteinDistance (strings) {
+    let first  = strings [0] . split ("");
+    let second = strings [1] . split ("");
+
+    let distance = [];
+
+    let N = first  . length;
+    let M = second . length;
+
+    for (let i = 0; i <= N; i ++) {
+        distance [i] = [];
+        for (let j = 0; j <= M; j ++) {
+            distance [i] [j] = 
+                i == 0 || j == 0 ? i + j
+              : Math . min (distance [i - 1] [j]     + 1,
+                            distance [i]     [j - 1] + 1,
+                            distance [i - 1] [j - 1] +
+                               (first  [i - 1] ==
+                                second [j - 1] ? 0 : 1))
+        }
+        if (i) {
+            distance [i - 1] = 0
+        }
+    }
+    return distance [N] [M]
+}
-- 
cgit 


From 7427859740c652344f72753829d12358b36f9807 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 18:52:27 +0100
Subject: AWK solution for week 96/part 2

---
 challenge-096/abigail/awk/ch-2.awk | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 challenge-096/abigail/awk/ch-2.awk

diff --git a/challenge-096/abigail/awk/ch-2.awk b/challenge-096/abigail/awk/ch-2.awk
new file mode 100644
index 0000000000..08cebccb4e
--- /dev/null
+++ b/challenge-096/abigail/awk/ch-2.awk
@@ -0,0 +1,26 @@
+#
+# Return the minimum of 3 values
+#
+function min (a, b, c) {
+    return a < b ? a < c ? a : c\
+                 : b < c ? b : c
+}
+
+#
+# This is an implementation of the Wagner Fischer algorithm, which
+# calculates the Levenshtein distance.
+#
+# See https://en.wikipedia.org/wiki/Wagner%E2%80%93Fischer_algorithm
+#
+{
+    for (i = 0; i <= length ($1); i ++) {
+        for (j = 0; j <= length ($2); j ++) {
+            distance [i, j] = i == 0 || j == 0 ? i + j\
+                     : min(distance [i - 1, j]     + 1,
+                           distance [i,     j - 1] + 1,
+                           distance [i - 1, j - 1] +\
+                           (substr ($1, i, 1) == substr ($2, j, 1) ? 0 : 1))
+        }
+    }
+    print distance [length ($1), length ($2)]
+}
-- 
cgit 


From d83a719fd0a80c8852e4187fe6f68e5833438417 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Jan 2021 20:43:51 +0100
Subject: C solution for week 96, part 2

---
 challenge-096/abigail/README.md |   2 +
 challenge-096/abigail/c/ch-2.c  | 128 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 challenge-096/abigail/c/ch-2.c

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index b19e1c3934..b15e417559 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -58,6 +58,8 @@ Operation 2: replace 'u' with 'o'
 ~~~~
 
 ### Solutions
+* [AWK](awk/ch-2.awk)
+* [C](c/ch-2.c)
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
 
diff --git a/challenge-096/abigail/c/ch-2.c b/challenge-096/abigail/c/ch-2.c
new file mode 100644
index 0000000000..73f35b1c0a
--- /dev/null
+++ b/challenge-096/abigail/c/ch-2.c
@@ -0,0 +1,128 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+# include <ctype.h>
+
+/*
+ * Return the minimum of three size_t values.
+ */
+size_t min3 (size_t a, size_t b, size_t c) {
+    return a < b ? a < c ? a : c
+                 : b < c ? b : c;
+}
+
+/*
+ * This is an implementation of the Wagner Fischer algorithm, which
+ * calculates the Levenshtein distance.
+ *
+ * See https://en.wikipedia.org/wiki/Wagner%E2%80%93Fischer_algorithm
+ */
+size_t LevenshteinDistance (char * first,  size_t n,
+                            char * second, size_t m) {
+      
+    /*
+     * If 'first' is the shorter string, swap the two strings.
+     * This reduces the memory usage.
+     */
+    if (n < m) {
+        char * tmp = first;
+        size_t t   = n;
+        first  = second;
+        second = tmp;
+        n      = m;
+        m      = t;
+    }
+
+    size_t ** distance;
+    if ((distance = malloc ((n + 1) * sizeof (size_t *))) == NULL) {
+        fprintf (stderr, "Out of memory\n");
+        exit (1);
+    }
+    for (size_t i = 0; i <= n; i ++) {
+        if ((distance [i] = malloc ((m + 1) * sizeof (size_t))) == NULL) {
+            fprintf (stderr, "Out of memory\n");
+            exit (1);
+        }
+        for (size_t j = 0; j <= m; j ++) {
+            distance [i] [j] = i == 0 || j == 0 ? i + j
+                   : min3 (distance [i - 1] [j]     + 1,
+                           distance [i]     [j - 1] + 1,
+                           distance [i - 1] [j - 1] +
+                             (first [i - 1] == second [j - 1] ? 0 : 1));
+        }
+        if (i) {
+            /*
+             * We only need the previous row; freeing the memory of rows
+             * we no longer need, reduces the memory usage from
+             * Theta (n * m) to O (min (n, m))
+             */
+            free (distance [i - 1]);
+        }
+    }
+    size_t out = distance [n] [m];
+    free (distance [n]);
+    free (distance);
+    return (out);
+}
+
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        /*
+         * Skip any leading whitespace
+         */
+        while (isspace (*line_ptr)) {
+            line_ptr ++;
+        }
+        /*
+         * We're now at the start of the first word;
+         * scan the word, count its length.
+         */
+        char * first = line_ptr;
+        size_t n     = 0;
+
+        while (!isspace (*line_ptr)) {
+            line_ptr ++;
+            n ++;
+        }
+
+        /*
+         * Terminate the first word, and advance our pointer.
+         */
+        *line_ptr ++ = '\0';
+
+        /*
+         * Skip over any subsequent whitespace
+         */
+        while (isspace (*line_ptr)) {
+            line_ptr ++;
+        }
+
+        /*
+         * We're now at the beginning of the second word;
+         * scan it, and count its length.
+         */
+        char * second = line_ptr;
+        size_t m      = 0;
+
+        while (*line_ptr && !isspace (*line_ptr)) {
+            line_ptr ++;
+            m ++;
+        }
+
+        /*
+         * Terminate the second word, before any trailing whitespace
+         */
+        *line_ptr ++ = '\0';
+
+        printf ("%zu\n", LevenshteinDistance (first, n, second, m));
+    }
+    free (line);
+
+    return (0);
+}
-- 
cgit 


From 244e676bc1ed3e802597168c002398615fbcb062 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 13:40:16 +0100
Subject: Fix order of solutions

---
 challenge-096/abigail/README.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index b15e417559..b0b0617ad2 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -20,8 +20,8 @@ Output: "family same the of part are Raku and Perl"
 ~~~~
 
 ### Solutions
-* [C](c/ch-1.c)
 * [AWK](awk/ch-1.awk)
+* [C](c/ch-1.c)
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
 * [Python](python/ch-1.py)
@@ -62,5 +62,6 @@ Operation 2: replace 'u' with 'o'
 * [C](c/ch-2.c)
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
+* [Python](python/ch-2.py)
 
 ### Blog
-- 
cgit 


From b3fd5101407177b4d9a8e2d41b3e063269cee6ba Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 13:42:51 +0100
Subject: Python solution for week 96, part 2.

---
 challenge-096/abigail/python/ch-2.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 challenge-096/abigail/python/ch-2.py

diff --git a/challenge-096/abigail/python/ch-2.py b/challenge-096/abigail/python/ch-2.py
new file mode 100644
index 0000000000..deaeff14cf
--- /dev/null
+++ b/challenge-096/abigail/python/ch-2.py
@@ -0,0 +1,21 @@
+import fileinput
+
+def LevenshteinDistance (first, second):
+    n = len (first)
+    m = len (second)
+    distance = []
+    for i in range (n + 1):
+        distance . append ([])
+        for j in range (m + 1):
+            distance [i] . append (i + j if i == 0 or j == 0 else
+                         min (distance [i - 1] [j]     + 1,
+                              distance [i]     [j - 1] + 1,
+                              distance [i - 1] [j - 1] +
+                                 (0 if first  [i - 1] ==
+                                       second [j - 1] else 1)))
+    return distance [n] [m]
+
+
+for line in fileinput . input ():
+    words = line . strip () . split ()
+    print LevenshteinDistance (words [0], words [1])
-- 
cgit 


From 6a8e97190d55b1e0f94318e4e0316e50de7415c0 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 13:43:39 +0100
Subject: lua solution for week 96, part 1

---
 challenge-096/abigail/README.md    |  1 +
 challenge-096/abigail/lua/ch-1.lua | 14 ++++++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 challenge-096/abigail/lua/ch-1.lua

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index b0b0617ad2..31f4073f0d 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -22,6 +22,7 @@ Output: "family same the of part are Raku and Perl"
 ### Solutions
 * [AWK](awk/ch-1.awk)
 * [C](c/ch-1.c)
+* [lua](lua/ch-1.lua)
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
 * [Python](python/ch-1.py)
diff --git a/challenge-096/abigail/lua/ch-1.lua b/challenge-096/abigail/lua/ch-1.lua
new file mode 100644
index 0000000000..68d1c5eb86
--- /dev/null
+++ b/challenge-096/abigail/lua/ch-1.lua
@@ -0,0 +1,14 @@
+for line in io . lines () do
+    --
+    -- Extract words and put them into an array, in reverse.
+    --
+    words = {}
+    for str in string . gmatch (line, "[^ ]+") do
+        table . insert (words, 1, str)
+    end
+
+    --
+    -- Print the words
+    --
+    io . write (table . concat (words, " "), "\n")
+end
-- 
cgit 


From b15a7dd19167fadcd7ef68d7807fb0915935fc5c Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 17:54:23 +0100
Subject: Make lua variables lexical

---
 challenge-096/abigail/lua/ch-1.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/challenge-096/abigail/lua/ch-1.lua b/challenge-096/abigail/lua/ch-1.lua
index 68d1c5eb86..9c4b1de913 100644
--- a/challenge-096/abigail/lua/ch-1.lua
+++ b/challenge-096/abigail/lua/ch-1.lua
@@ -2,7 +2,7 @@ for line in io . lines () do
     --
     -- Extract words and put them into an array, in reverse.
     --
-    words = {}
+    local words = {}
     for str in string . gmatch (line, "[^ ]+") do
         table . insert (words, 1, str)
     end
-- 
cgit 


From aafab4118e1ed9b94a7f2c16cf4457d79ab53f77 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 18:53:19 +0100
Subject: lua solution for week 96, part 2

---
 challenge-096/abigail/README.md    |  1 +
 challenge-096/abigail/lua/ch-2.lua | 56 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 challenge-096/abigail/lua/ch-2.lua

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index 31f4073f0d..b80b3476b1 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -61,6 +61,7 @@ Operation 2: replace 'u' with 'o'
 ### Solutions
 * [AWK](awk/ch-2.awk)
 * [C](c/ch-2.c)
+* [lua](lua/ch-2.lua)
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
 * [Python](python/ch-2.py)
diff --git a/challenge-096/abigail/lua/ch-2.lua b/challenge-096/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..bb1b042b19
--- /dev/null
+++ b/challenge-096/abigail/lua/ch-2.lua
@@ -0,0 +1,56 @@
+--
+-- This is an implementation of the Wagner Fischer algorithm, which
+-- calculates the Levenshtein distance.
+--
+-- See https://en.wikipedia.org/wiki/Wagner%E2%80%93Fischer_algorithm
+--
+function LevenshteinDistance (first, second)
+    local n = first  : len ()
+    local m = second : len ()
+    if n < m
+    then
+        first, second = second, first
+        n,     m      = m,      n
+    end
+    distances = {}
+    for i = 0, n do
+        distances [i] = {}
+        for j = 0, m do
+            if i == 0 or j == 0
+            then
+                distances [i] [j] = i + j
+            else
+                local cost = 1
+                if string . sub (first,  i, i) ==
+                   string . sub (second, j, j)
+                then
+                    cost = 0
+                end
+                distances [i] [j] = math . min (
+                    distances [i - 1] [j]     + 1,
+                    distances [i]     [j - 1] + 1,
+                    distances [i - 1] [j - 1] + cost
+                )
+            end
+        end
+    end
+    return distances [n] [m]
+end
+
+
+for line in io . lines () do
+    --
+    -- Extract words and put them into an array.
+    --
+    local words = {}
+    index = 0
+    for str in string . gmatch (line, "[^ ]+") do
+        index = index + 1
+        words [index] = str
+    end
+
+    --
+    -- Calculate the edit distance, and print the result.
+    --
+    io . write (LevenshteinDistance (words [1], words [2]), "\n")
+end
-- 
cgit 


From 8efd5eca4066257d8d39aa1f25481b09e8bc7689 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 19:45:56 +0100
Subject: Bash solution for week 96, part 1

---
 challenge-096/abigail/README.md    |  1 +
 challenge-096/abigail/bash/ch-1.sh | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 challenge-096/abigail/bash/ch-1.sh

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index b80b3476b1..3582807374 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -21,6 +21,7 @@ Output: "family same the of part are Raku and Perl"
 
 ### Solutions
 * [AWK](awk/ch-1.awk)
+* [bash](sh/ch-1.sh)
 * [C](c/ch-1.c)
 * [lua](lua/ch-1.lua)
 * [Node.js](node/ch-1.js)
diff --git a/challenge-096/abigail/bash/ch-1.sh b/challenge-096/abigail/bash/ch-1.sh
new file mode 100644
index 0000000000..9122fae4e0
--- /dev/null
+++ b/challenge-096/abigail/bash/ch-1.sh
@@ -0,0 +1,21 @@
+#
+# Read in a line from STDIN, split it on whitespace,
+# put the result into an array 'words'
+#
+while read -a words
+do
+     #
+     # Iterate over the words backwards, and print them.
+     #
+     for   ((i = ${#words[@]} - 1; i >= 0; i --));
+     do   printf "%s" ${words[$i]}
+          #
+          # Print a newline after the final word; otherwise,
+          # print a space.
+          #
+          if    (($i == 0))
+          then  printf "\n"
+          else  printf " "
+          fi
+     done
+done
-- 
cgit 


From 8ed013c57480f076ff5da48f18b2ca86a86c4bba Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 20:22:03 +0100
Subject: Ruby solution for week 96, part 2

---
 challenge-096/abigail/README.md    |  3 ++-
 challenge-096/abigail/ruby/ch-2.rb | 31 +++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 challenge-096/abigail/ruby/ch-2.rb

diff --git a/challenge-096/abigail/README.md b/challenge-096/abigail/README.md
index 3582807374..d715618651 100644
--- a/challenge-096/abigail/README.md
+++ b/challenge-096/abigail/README.md
@@ -27,7 +27,7 @@ Output: "family same the of part are Raku and Perl"
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
 * [Python](python/ch-1.py)
-* [Ruby](ruby/ch-1.py)
+* [Ruby](ruby/ch-1.rb)
 
 ### Blog
 
@@ -66,5 +66,6 @@ Operation 2: replace 'u' with 'o'
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
 * [Python](python/ch-2.py)
+* [Ruby](ruby/ch-2.rb)
 
 ### Blog
diff --git a/challenge-096/abigail/ruby/ch-2.rb b/challenge-096/abigail/ruby/ch-2.rb
new file mode 100644
index 0000000000..65a57bd6d3
--- /dev/null
+++ b/challenge-096/abigail/ruby/ch-2.rb
@@ -0,0 +1,31 @@
+def LevenshteinDistance (first, second)
+    n = first  . length
+    m = second . length
+    if n < m
+        first, second = second, first
+        n,     m      = m,      n
+    end
+    distances = []
+    for i in 0 .. n do
+        distances [i] = []
+        for j in 0 .. m do
+            distances [i] [j] = i == 0 || j == 0 ? i + j
+                    : [distances [i - 1] [j]     + 1,
+                       distances [i]     [j - 1] + 1,
+                       distances [i - 1] [j - 1] +
+                          (first [i - 1] == second [j - 1] ? 0 : 1)] . min
+        end
+        #
+        # Release memory
+        #
+        if i > 1
+            distances [i - 1] = nil
+        end
+    end
+    return distances [n] [m]
+end
+
+ARGF . each_line do |_|
+    words = (_ . split (/\s+/)) . grep (/\S/)
+    puts (LevenshteinDistance words [0], words [1])
+end
-- 
cgit 


From a7e6309b32bacaac724e734572f4017a6da70448 Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 22:00:40 +0100
Subject: Deal with leading and trailing whitespace.

---
 challenge-096/abigail/node/ch-2.js     | 3 ++-
 challenge-096/abigail/t/ctest.ini      | 5 +++++
 challenge-096/abigail/t/input-2-3      | 1 +
 challenge-096/abigail/t/output-2-3.exp | 1 +
 4 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 challenge-096/abigail/t/input-2-3
 create mode 100644 challenge-096/abigail/t/output-2-3.exp

diff --git a/challenge-096/abigail/node/ch-2.js b/challenge-096/abigail/node/ch-2.js
index 03f423b2ec..8423ab96b8 100644
--- a/challenge-096/abigail/node/ch-2.js
+++ b/challenge-096/abigail/node/ch-2.js
@@ -6,7 +6,8 @@
 . toString     ()                // Turn it into a string.
 . split        ("\n")            // Split on newlines.
 . filter       (_ => _ . length) // Filter out empty lines.
-. map          (_ => console . log (LevenshteinDistance (_ . split (/\s+/))))
+. map          (_ => console . log (LevenshteinDistance (_ . trim () 
+                                                           . split (/\s+/))))
 ;
 
 //
diff --git a/challenge-096/abigail/t/ctest.ini b/challenge-096/abigail/t/ctest.ini
index 99eb989ad5..5592956f87 100644
--- a/challenge-096/abigail/t/ctest.ini
+++ b/challenge-096/abigail/t/ctest.ini
@@ -2,7 +2,12 @@
 1-1 = Given examples
 2-1 = Given examples
 2-2 = Wikipedia example
+2-3 = Extra whitespace
 
 
 [1-1]
 trim = 0
+
+
+[2-3]
+trim = 0
diff --git a/challenge-096/abigail/t/input-2-3 b/challenge-096/abigail/t/input-2-3
new file mode 100644
index 0000000000..80a194e95c
--- /dev/null
+++ b/challenge-096/abigail/t/input-2-3
@@ -0,0 +1 @@
+  hello   world    
diff --git a/challenge-096/abigail/t/output-2-3.exp b/challenge-096/abigail/t/output-2-3.exp
new file mode 100644
index 0000000000..b8626c4cff
--- /dev/null
+++ b/challenge-096/abigail/t/output-2-3.exp
@@ -0,0 +1 @@
+4
-- 
cgit 


From 053b0ef31a9cddae0cbd792ad539b2d68876538c Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Tue, 19 Jan 2021 22:01:14 +0100
Subject: lua/ch-2.lua: Save some memory.

---
 challenge-096/abigail/lua/ch-2.lua | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/challenge-096/abigail/lua/ch-2.lua b/challenge-096/abigail/lua/ch-2.lua
index bb1b042b19..162f06eef0 100644
--- a/challenge-096/abigail/lua/ch-2.lua
+++ b/challenge-096/abigail/lua/ch-2.lua
@@ -33,6 +33,16 @@ function LevenshteinDistance (first, second)
                 )
             end
         end
+
+        --
+        -- We only need the previous row, so we can return the
+        -- memory of rows before that. This reduces the memory
+        -- usage from O (n * m) to O (min (n, m))
+        --
+        if i > 0
+        then
+            distances [i - 1] = nil
+        end
     end
     return distances [n] [m]
 end
-- 
cgit