1 files changed, 76 insertions, 0 deletions
diff --git a/challenge-220/roger-bell-west/lua/ch-1.lua b/challenge-220/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..74624b0e7e
--- /dev/null
+++ b/challenge-220/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,76 @@
+#! /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 keys(t)
+   local a = {}
+   for k, v in pairs(t) do
+      table.insert(a, k)
+   end
+   return a
+end
+
+function word2set(word)
+   local s = {}
+   for c in string.gmatch(string.lower(word), "%a") do
+      s[c] = true
+   end
+   return s
+end
+
+function commoncharacters(lst)
+   local c = word2set(lst[1])
+   for i = 2, #lst do
+      local d = word2set(lst[i])
+      for k, _ in pairs(c) do
+         if d[k] == nil then
+            c[k] = nil
+         end
+      end
+   end
+   local o = keys(c)
+   table.sort(o)
+   return o
+end
+
+if recursive_compare(commoncharacters({"Perl", "Rust", "Raku"}), {"r"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"love", "live", "leave"}), {"e", "l", "v"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+