1 files changed, 104 insertions, 0 deletions
diff --git a/challenge-159/roger-bell-west/lua/ch-1.lua b/challenge-159/roger-bell-west/lua/ch-1.lua
new file mode 100755
index 0000000000..d10299f584
--- /dev/null
+++ b/challenge-159/roger-bell-west/lua/ch-1.lua
@@ -0,0 +1,104 @@
+#! /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 gcd(m0,n0)
+   local m,n = m0,n0
+   while n ~= 0 do
+      m,n = n,m % n
+   end
+   return m
+end
+
+function lcm(m,n)
+   return m/gcd(m,n)*n
+end
+
+function lcmseries(a,b)
+   local t=1
+   for v = a,b do
+      t = lcm(t,v)
+   end
+   return t
+end
+
+function farey(n)
+   local l=lcmseries(2,n)
+   local d={}
+   local s={}
+   for i = 1,n do
+      local m = l / i
+      for j = 0,i do
+         local k = m * j
+         if d[k] == nil then
+            d[k] = {j,i}
+            table.insert(s,k)
+         end
+      end
+   end
+   table.sort(s)
+   local out={}
+   for k,v in ipairs(s) do
+      table.insert(out,d[v])
+   end
+   return out
+end
+
+if recursive_compare(farey(5),{
+                        {0, 1}, {1, 5}, {1, 4}, {1, 3}, {2, 5},
+                        {1, 2}, {3, 5}, {2, 3}, {3, 4}, {4, 5},
+                        {1, 1}
+                    }) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(farey(7),{
+                        {0, 1}, {1, 7}, {1, 6}, {1, 5}, {1, 4},
+                        {2, 7}, {1, 3}, {2, 5}, {3, 7}, {1, 2},
+                        {4, 7}, {3, 5}, {2, 3}, {5, 7}, {3, 4},
+                        {4, 5}, {5, 6}, {6, 7}, {1, 1}
+                    }) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+io.write(" ")
+
+if recursive_compare(farey(4),{
+                        {0, 1}, {1, 4}, {1, 3}, {1, 2}, {2, 3},
+                        {3, 4}, {1, 1}
+                    }) then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+print("")