RogerBW solutions for challenge no. 321

1 files changed, 58 insertions, 0 deletions

diff --git a/challenge-321/roger-bell-west/lua/ch-2.lua b/challenge-321/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..60d4d80aa7
--- /dev/null
+++ b/challenge-321/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,58 @@
+#! /usr/bin/lua
+
+function split(t)
+   local cl = {}
+   string.gsub(t,
+               "(.)",
+               function(c)
+                  table.insert(cl, c)
+               end
+   )
+   return cl
+end
+
+function join(t)
+   local out=""
+   for i, v in ipairs(t) do
+      out = out .. v
+   end
+   return out
+end
+
+function backspacecompare(a, b)
+   local sa = {}
+   for _, i in ipairs({a, b}) do
+      local oa = {}
+      for _n, c in ipairs(split(i)) do
+         if c == "#" then
+            table.remove(oa, #oa)
+         else
+            table.insert(oa, c)
+         end
+      end
+      table.insert(sa, join(oa))
+   end
+   return sa[1] == sa[2]
+end
+
+if backspacecompare("ab#c", "ad#c") then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if backspacecompare("ab##", "a#b#") then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+io.write(" ")
+
+if not backspacecompare("a#b", "c") then
+  io.write("Pass")
+else
+  io.write("FAIL")
+end
+print("")
+