1 files changed, 29 insertions, 0 deletions
diff --git a/challenge-123/stuart-little/lua/ch-2.lua b/challenge-123/stuart-little/lua/ch-2.lua
new file mode 100755
index 0000000000..6fe2c55aad
--- /dev/null
+++ b/challenge-123/stuart-little/lua/ch-2.lua
@@ -0,0 +1,29 @@
+#!/usr/bin/env lua
+
+-- run <script> <x1 y1 x2 y2 ..>
+
+function sqDist(coords)
+    return (coords[3]-coords[1])^2 + (coords[4]-coords[2])^2
+end
+
+function sqDistHash(coords)
+   local t={}
+   for i=1,3 do
+      for j=i+1,4 do
+	 local d=sqDist({coords[2*i-1],coords[2*i],coords[2*j-1],coords[2*j]})
+	 t[d] = t[d] and t[d]+1 or 1
+      end
+   end
+   return t
+end
+
+function isSq(coords)
+   local records=0
+   for k,v in pairs(sqDistHash(coords)) do
+      if k==0 then return false end
+      if v==2 or v==4 then records=records+1 end
+   end
+   return records==2
+end
+
+print(isSq(table.pack(table.unpack(arg,1,8))) and 1 or 0)