Merge remote-tracking branch 'upstream/master'

1 files changed, 49 insertions, 0 deletions

diff --git a/challenge-104/abigail/lua/ch-1a.lua b/challenge-104/abigail/lua/ch-1a.lua
new file mode 100644
index 0000000000..16569bf822
--- /dev/null
+++ b/challenge-104/abigail/lua/ch-1a.lua
@@ -0,0 +1,49 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-1a.lua
+--
+
+--
+-- Initialize the cache
+--
+
+local cache = {}
+cache [0] =  0
+cache [1] =  1
+local max = 50
+
+--
+-- Fusc sequence is defined as:
+--            ( n,                                        0 <= n <= 1
+-- fusc (n) = { fusc  (n / 2),                            n > 1 && n even
+--            ( fusc ((n - 1) / 2) + fusc ((n + 1) / 2),  n > 1 && n odd
+--
+
+function fusc (n)
+    if cache [n] == nil then
+        if n % 2 == 1 then
+            cache [n] = fusc ((n - 1) / 2) + fusc ((n + 1) / 2)
+        else
+            cache [n] = fusc (n / 2)
+        end
+    end
+    return cache [n]
+end
+
+
+--
+-- Calculate the values and print them
+--
+
+for i = 0, max - 1 do
+    if i > 0
+    then io . write (" ")
+    end
+    io . write (fusc (i))
+end
+io . write ("\n")