1 files changed, 74 insertions, 0 deletions
diff --git a/challenge-263/roger-bell-west/lua/ch-2.lua b/challenge-263/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..3c0188c1b1
--- /dev/null
+++ b/challenge-263/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,74 @@
+#! /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 mergeitems(a, b)
+   local c = {}
+   for i, v in ipairs({a, b}) do
+      for j, w in ipairs(v) do
+         if c[w[1]] == nil then
+            c[w[1]] = 0
+         end
+         c[w[1]] = c[w[1]] + w[2]
+      end
+   end
+   local k = {}
+   for t, _ in pairs(c) do
+      table.insert(k, t)
+   end
+   table.sort(k)
+   local out = {}
+   for _, i in ipairs(k) do
+      table.insert(out, {i, c[i]})
+   end
+   return out
+end
+
+if recursive_compare(mergeitems({{1, 1}, {2, 1}, {3, 2}}, {{2, 2}, {1, 3}}), {{1, 4}, {2, 3}, {3, 2}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(mergeitems({{1, 2}, {2, 3}, {1, 3}, {3, 2}}, {{3, 1}, {1, 3}}), {{1, 8}, {2, 3}, {3, 3}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(mergeitems({{1, 1}, {2, 2}, {3, 3}}, {{2, 3}, {2, 4}}), {{1, 1}, {2, 9}, {3, 3}}) then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+