1 files changed, 111 insertions, 0 deletions
diff --git a/challenge-172/roger-bell-west/lua/ch-1.lua b/challenge-172/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..82e7553e65
--- /dev/null
+++ b/challenge-172/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,111 @@
+#! /usr/bin/lua
+
+-- by Michael Anderson at
+-- https://stackoverflow.com/questions/8722620/comparing-two-index-tables-by-index-value-in-lua
+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
+
+  -- Check each key-value pair
+  -- We have to do this both ways in case we miss some.
+  -- TODO: Could probably be smarter and not check those we've 
+  -- already checked though!
+  for k1,v1 in pairs(t1) do
+    local v2 = t2[k1]
+    if( not recursive_compare(v1,v2) ) then return false end
+  end
+  for k2,v2 in pairs(t2) do
+    local v1 = t1[k2]
+    if( not recursive_compare(v1,v2) ) then return false end
+  end
+
+  return true  
+end
+
+function genprimes(mx)
+   local primesh = {}
+   for i = 2, 3 do
+      primesh[i] = true
+   end
+   for i = 6, mx, 6 do
+      for j = i-1, i+1, 2 do
+         if j <= mx then
+            primesh[j]=true
+         end
+      end
+   end
+   local q={2,3,5,7}
+   local p=table.remove(q,1)
+   local mr=math.floor(math.sqrt(mx))
+   while p <= mr do
+      if primesh[p] ~= nil then
+         for i = p*p,mx,p do
+            primesh[i] = nil
+         end
+      end
+      if #q < 2 then
+         table.insert(q,q[#q]+4)
+         table.insert(q,q[#q]+2)
+      end
+      p=table.remove(q,1)
+   end
+   local primes = {}
+   for k,v in pairs(primesh) do
+      table.insert(primes,k)
+   end
+   table.sort(primes)
+   return primes
+end
+
+function primepartition(n, divs)
+   local pl = genprimes(n)
+   local p = {{}}
+   while #p > 0 do
+      local pa = table.remove(p)
+      if #pa == divs then
+         local sum = 0
+         for i,v in ipairs(pa) do
+            sum = sum + v
+         end
+         if sum == n then
+            return pa
+         end
+      else
+         local px = {}
+         for i,v in ipairs(pa) do
+            px[v] = true
+         end
+         for i,pq in ipairs(pl) do
+            if px[pq] == nil then
+               local pb = {}
+               for j,pk in ipairs(pa) do
+                  table.insert(pb,pk)
+               end
+               table.insert(pb,pq)
+               table.insert(p,pb)
+            end
+         end
+      end
+   end
+   return {n}
+end
+
+if recursive_compare(primepartition(18,2), {13, 5}) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(primepartition(19,3), {11, 5, 3}) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+print("")