1 files changed, 79 insertions, 0 deletions
diff --git a/challenge-249/roger-bell-west/lua/ch-2.lua b/challenge-249/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..4ce75b8aff
--- /dev/null
+++ b/challenge-249/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,79 @@
+#! /usr/bin/lua
+
+-- by Michael Anderson at
+-- https://stackoverflow.com/questions/8722620/comparing-two-index-tables-by-index-value-in-lua
+-- modified by Roger
+function recursive_compare(t1,t2)
+  -- Use usual comparison first.
+  if t1==t2 then return true end
+  -- We only support non-default behavior for tables
+  if (type(t1)~="table") then return false end
+  -- They better have the same metatables
+  local mt1 = getmetatable(t1)
+  local mt2 = getmetatable(t2)
+  if( not recursive_compare(mt1,mt2) ) then return false end
+  -- Build list of all keys
+  local kk = {}
+  for k1, _ in pairs(t1) do
+     kk[k1] = true
+  end
+  for k2, _ in pairs(t2) do
+     kk[k2] = true
+  end
+  -- Check each key that exists in at least one table
+  for _, k in ipairs(kk) do
+     if (not recursive_compare(t1[k], t2[k])) then
+        return false
+     end
+  end
+  return true
+end
+
+function distringmatch(a)
+   local v = 1 << (#a - 1)
+   local wv = v << 1
+   local out = {wv}
+   local r = {wv}
+   for c in string.gmatch(a, ".") do
+      if c == "I" then
+         wv = wv + v
+      else
+         wv = wv - v
+      end
+      v = v >> 1
+      table.insert(out, wv)
+      table.insert(r, wv)
+   end
+   table.sort(r)
+   local c = {}
+   for i = 1, #r do
+      c[r[i]] = i
+   end
+   local o = {}
+   for _, n in ipairs(out) do
+      table.insert(o, c[n])
+   end
+   return o
+end
+
+if recursive_compare(distringmatch("IDID"), {0, 4, 1, 3, 2}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(distringmatch("III"), {0, 1, 2, 3}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(distringmatch("DDI"), {3, 2, 0, 1}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+