Lua solution for week 100, part 2

2 files changed, 42 insertions, 0 deletions

diff --git a/challenge-100/abigail/README.md b/challenge-100/abigail/README.md
index c3d1134d80..7e4cf910e0 100644
--- a/challenge-100/abigail/README.md
+++ b/challenge-100/abigail/README.md
@@ -82,6 +82,7 @@ The minimum path sum from top to bottom: 3 + 1 + 2 + 1 = 7
 * [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)
 
 ### Blog
diff --git a/challenge-100/abigail/lua/ch-2.lua b/challenge-100/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..d3e3b3b1d1
--- /dev/null
+++ b/challenge-100/abigail/lua/ch-2.lua
@@ -0,0 +1,41 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+local numbers = {}
+
+--
+-- Read in the data
+--
+for line in io . lines () do
+    local row = {}
+    for n in line : gsub ("\n", "") : gmatch ("-?%d+") do
+        table . insert (row, n)
+    end
+    table . insert (numbers, row)
+end
+
+--
+-- Calculate minimum path, bottom to top
+--
+for x = #numbers - 1, 1, -1 do
+    local row = numbers [x]
+    for y = 1, #row do
+        min =      numbers [x + 1] [y]
+        if         numbers [x + 1] [y + 1] < min
+        then min = numbers [x + 1] [y + 1]
+        end
+        numbers [x] [y] = numbers [x] [y] + min
+    end 
+end
+
+--
+-- Print result
+--
+print (numbers [1] [1])