1 files changed, 53 insertions, 0 deletions
diff --git a/challenge-182/roger-bell-west/lua/ch-2.lua b/challenge-182/roger-bell-west/lua/ch-2.lua
new file mode 100755
index 0000000000..08c63996aa
--- /dev/null
+++ b/challenge-182/roger-bell-west/lua/ch-2.lua
@@ -0,0 +1,53 @@
+#! /usr/bin/lua
+
+-- bart at https://stackoverflow.com/questions/1426954/split-string-in-lua
+function split(inputstr, sep)
+   sep=sep or '%s'
+   local t={}
+   for field,s in string.gmatch(inputstr, "([^"..sep.."]*)("..sep.."?)") do
+      table.insert(t,field)
+      if s=="" then
+         return t
+      end
+   end
+end
+   
+
+function commonpath(p)
+   local pa = {}
+   local pl = {}
+   for i, sp in ipairs(p) do
+      local q = split(sp, "/")
+      table.insert(pl,#q)
+      table.insert(pa,q)
+   end
+   local out = {}
+   for cl = 1,math.min(table.unpack(pl)) do
+      local ex = false
+      local tx = pa[1][cl]
+      for i, pe in ipairs(pa) do
+         if pe[cl] ~= tx then
+            ex = true
+            break
+         end
+      end
+      if ex then
+         break
+      end
+      table.insert(out,tx)
+   end
+   return table.concat(out,"/")
+end
+
+if commonpath({
+      "/a/b/c/1/x.pl",
+      "/a/b/c/d/e/2/x.pl",
+      "/a/b/c/d/3/x.pl",
+      "/a/b/c/4/x.pl",
+      "/a/b/c/d/5/x.pl"
+             }) == "/a/b/c" then
+   io.write("Pass")
+else
+   io.write("FAIL")
+end
+print("")