1 files changed, 123 insertions, 0 deletions
diff --git a/challenge-335/roger-bell-west/lua/ch-1.lua b/challenge-335/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..200f658fec
--- /dev/null
+++ b/challenge-335/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,123 @@
+#! /usr/bin/lua
+
+function commoncharacters(a)
+   local mc = {}
+   for sn, s in ipairs(a) do
+      local mk = counterify(split(s))
+      if sn == 1 then
+         mc = mk
+      else
+         for k, _v in pairs(mc) do
+            if mk[k] ~= nil then
+               mc[k] = math.min(mc[k], mk[k])
+            else
+               mc[k] = nil
+            end
+         end
+      end
+   end
+   local out = {}
+   local kl = keys(mc)
+   table.sort(kl)
+   for _, c in ipairs(kl) do
+      for n = 1, mc[c] do
+         table.insert(out, c)
+      end
+   end
+   return out
+end
+
+function keys(t)
+   local a = {}
+   for k, v in pairs(t) do
+      table.insert(a, k)
+   end
+   return a
+end
+
+function counterify(a)
+   local cc = {}
+   for _, c in ipairs(a) do
+      if cc[c] == nil then
+         cc[c] = 0
+      end
+      cc[c] = cc[c] + 1
+   end
+   return cc
+end
+
+function split(t)
+   local cl = {}
+   string.gsub(t,
+               "(.)",
+               function(c)
+                  table.insert(cl, c)
+               end
+   )
+   return cl
+end
+
+-- 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
+
+if recursive_compare(commoncharacters({"bella", "label", "roller"}), {"e", "l", "l"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"cool", "lock", "cook"}), {"c", "o"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"hello", "world", "pole"}), {"l", "o"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"abc", "def", "ghi"}), {}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(commoncharacters({"aab", "aac", "aaa"}), {"a", "a"}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+