Lua solutions for week 136

2 files changed, 62 insertions, 0 deletions

diff --git a/challenge-136/abigail/lua/ch-1.lua b/challenge-136/abigail/lua/ch-1.lua
new file mode 100644
index 0000000000..182d18fba7
--- /dev/null
+++ b/challenge-136/abigail/lua/ch-1.lua
@@ -0,0 +1,42 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-1.lua < input-file
+--
+
+--
+-- Find the GCD, using Euclids algorithm
+--    (https://en.wikipedia.org/wiki/Euclidean_algorithm#Implementations)
+--
+function gcd (a, b)
+    while b > 0 do
+        a, b = b, a % b
+    end
+    return a
+end
+
+--
+-- Precalculate all the relevant powers of 2. Note that in pre 5-3 lua
+-- integers are doubles, and start losing precision at 2^53, so we go
+-- up to 2^52.
+--
+local power_of_2 = {}
+local power      = 1
+for i = 1, 52 do
+    power = power * 2
+    power_of_2 [power] = 1
+end
+
+
+for line in io . lines () do
+    local _, _, n, m = line : find ("([0-9]+)%s+([0-9]+)")
+    if power_of_2 [gcd (tonumber (n), tonumber (m))] then
+        print (1)
+    else
+        print (0)
+    end
+end
diff --git a/challenge-136/abigail/lua/ch-2.lua b/challenge-136/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..d403ce64d6
--- /dev/null
+++ b/challenge-136/abigail/lua/ch-2.lua
@@ -0,0 +1,20 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+function count (target, this_fib, prev_fib)
+    if target <  this_fib then return 0 end
+    if target == this_fib then return 1 end
+    return (count (target - this_fib, this_fib + prev_fib, this_fib) +
+            count (target,            this_fib + prev_fib, this_fib))
+end
+
+for line in io . lines () do
+    print (count (tonumber (line), 1, 1))
+end