Merge branch 'master' of github.com:manwar/perlweeklychallenge-club into challenges

1 files changed, 59 insertions, 0 deletions

diff --git a/challenge-115/abigail/lua/ch-2.lua b/challenge-115/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..4b92535d53
--- /dev/null
+++ b/challenge-115/abigail/lua/ch-2.lua
@@ -0,0 +1,59 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+local NR_OF_DIGITS = 10
+
+for line in io . lines () do
+
+    -- 
+    -- Process the input, count digits
+    --
+    local digits = {}
+    for i = 0, NR_OF_DIGITS - 1
+    do  digits [i] = 0
+    end
+    for d in line : gmatch ("%d")
+    do  d = tonumber (d)
+        digits [d] = digits [d] + 1
+    end
+
+    -- 
+    -- Find the lowest even digit
+    --
+    local last = -1
+    for i = NR_OF_DIGITS - 2, 0, -2
+    do  if   digits [i] > 0
+        then last = i
+        end
+    end
+
+    --
+    -- Skip if there is no even digit in the input
+    --
+    if   last < 0
+    then goto end_loop
+    end
+
+    digits [last] = digits [last] - 1
+
+    --
+    -- Create output: digits from high to low
+    --
+    local out = ""
+    for i = NR_OF_DIGITS - 1, 0, -1
+    do  for j = 1, digits [i]
+        do  out = out .. tostring (i)
+        end
+    end
+
+    print (out .. tostring (last))
+
+    ::end_loop::
+end