Merge pull request #4120 from Abigail/abigail/week-113

Abigail/week 113

1 files changed, 46 insertions, 0 deletions

diff --git a/challenge-113/abigail/lua/ch-1.lua b/challenge-113/abigail/lua/ch-1.lua
new file mode 100644
index 0000000000..4de70d106c
--- /dev/null
+++ b/challenge-113/abigail/lua/ch-1.lua
@@ -0,0 +1,46 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-1.lua < input-file
+--
+
+--     
+-- For a description of the algorithm, and the proof why this is correct:
+-- https://abigail.github.io/HTML/Perl-Weekly-Challenge/week-113-1.html
+--  
+
+local gcds = {1, 2, 1, 2, 5, 2, 1, 2, 1}
+
+for  line in io . lines () do
+     local _, _, N, D = line : find ("([0-9]+)%s+([0-9])")
+     N = tonumber (N)
+     D = tonumber (D)
+     if   D == 0
+     then if   N >= 100 or N % 10 == 0
+          then print (1)
+          else print (0)
+          end
+          goto end_loop
+     end
+
+     if   N >= D * 10
+     then print (1)
+          goto end_loop
+     end
+ 
+     for  i = 0, D / gcds [D] - 1
+     do   local T = N - 10 * i - D
+          if   T >= 0 and T % D == 0
+          then print (1)
+               goto end_loop
+          end
+     end
+
+     print (0)
+  
+     ::end_loop::
+end