RogerBW solutions for challenge no. 219

1 files changed, 64 insertions, 0 deletions

diff --git a/challenge-219/roger-bell-west/lua/ch-2.lua b/challenge-219/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..303ebc51db
--- /dev/null
+++ b/challenge-219/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,64 @@
+#! /usr/bin/lua
+
+function propersize(t)
+   local l=0
+   for k,v in pairs(t) do
+      l = l + 1
+   end
+   return l
+end
+
+function keys(t)
+   local a = {}
+   for k, v in pairs(t) do
+      table.insert(a, k)
+   end
+   return a
+end
+
+function travelexpenditure(costs, days0)
+   local days = days0
+   table.sort(days)
+   local validities = {1, 7, 30}
+   local stack = {}
+   table.insert(stack, {0, days})
+   local cheapest = #days * costs[1]
+   while #stack > 0 do
+      local c = table.remove(stack, 1)
+      if #(c[2]) == 0 then
+         if c[1] < cheapest then
+            cheapest = c[1]
+         end
+      else
+         if c[1] < cheapest then
+            local start = c[2][1]
+            for i = 1, 3 do
+               local ed = start + validities[i] - 1
+               local dtd = {}
+               for _, j in ipairs(c[2]) do
+                  if j > ed then
+                     table.insert(dtd , j)
+                  end
+               end
+               table.insert(stack, {c[1] + costs[i], dtd})
+            end
+         end
+      end
+   end
+   return cheapest
+end
+
+if travelexpenditure({2, 7, 25}, {1, 5, 6, 7, 9, 15}) == 11 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if travelexpenditure({2, 7, 25}, {1, 2, 3, 5, 7, 10, 11, 12, 14, 20, 30, 31}) == 20 then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+