Merge pull request #8860 from deadmarshal/TWC238

TWC238

1 files changed, 32 insertions, 0 deletions

diff --git a/challenge-238/deadmarshal/lua/ch-2.lua b/challenge-238/deadmarshal/lua/ch-2.lua
new file mode 100644
index 0000000000..660235f0bb
--- /dev/null
+++ b/challenge-238/deadmarshal/lua/ch-2.lua
@@ -0,0 +1,32 @@
+#!/usr/bin/env lua
+
+local function product(n)
+  assert(type(n) == 'number','n must be a number!')
+  local prod = 1
+  while n > 0 do
+    prod = prod * (n % 10)
+    n = n // 10
+  end
+  return prod
+end
+
+local function helper(n)
+  assert(type(n) == 'number','n must be a number!')
+  local sum = 0
+  repeat
+    sum = sum + 1
+    n = product(n)
+  until n < 10
+  return sum
+end
+
+local function persistence_sort(t)
+  assert(type(t) == 'table','t must be a table!')
+  table.sort(t,function(a,b) return helper(a) < helper(b) or
+		 a < b end)
+  print(table.unpack(t))
+end
+
+persistence_sort{15,99,1,34}
+persistence_sort{50,25,33,22}
+