Lua solution for week 102, part 2

2 files changed, 37 insertions, 0 deletions

diff --git a/challenge-102/abigail/README.md b/challenge-102/abigail/README.md
index b54125f5aa..06252fc7d3 100644
--- a/challenge-102/abigail/README.md
+++ b/challenge-102/abigail/README.md
@@ -88,4 +88,5 @@ such length-`N` string.
 * [AWK](awk/ch-2.awk)
 * [Bash](bash/ch-2.sh)
 * [C](c/ch-2.c)
+* [Lua](lua/ch-2.lua)
 * [Perl](perl/ch-2.pl)
diff --git a/challenge-102/abigail/lua/ch-2.lua b/challenge-102/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..bbeb2a13ae
--- /dev/null
+++ b/challenge-102/abigail/lua/ch-2.lua
@@ -0,0 +1,36 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+--
+-- Working from the end of the required string backwards, we alternate
+-- placing a hash, and placing a number. We place them in an array out,
+-- and at the end, print out said array in reverse order.
+--
+for index in io . lines () do
+    index = tonumber (index)
+    out = {}
+    hash = false
+    i = 0
+    while index > 0 do
+        hash = not hash
+        i = i + 1
+        if  hash then
+            out [i] = "#"
+            index = index - 1
+        else 
+            out [i] = index + 1
+            index = index - tostring (index + 1) : len ()
+        end
+    end
+    for j = i, 1, -1 do
+        io . write (out [j])
+    end
+    io . write ("\n")
+end