Use recursive algorithms for GCD

3 files changed, 12 insertions, 15 deletions

diff --git a/challenge-136/abigail/bash/ch-1.sh b/challenge-136/abigail/bash/ch-1.sh
index 5e7b17da18..9c3ac91402 100644
--- a/challenge-136/abigail/bash/ch-1.sh
+++ b/challenge-136/abigail/bash/ch-1.sh
@@ -15,13 +15,12 @@
 function gcd () {
     local a=$1
     local b=$2
-    local t=0
-    while ((b != 0))
-    do    ((t = b))
-          ((b = a % b))
-          ((a = t))
-    done
-    ((gcd = a))
+    if   ((b > a))
+    then gcd $b $a
+    elif ((b == 0))
+    then gcd=$a
+    else gcd $b $((a % b))
+    fi
 }
 
 set -f
diff --git a/challenge-136/abigail/lua/ch-1.lua b/challenge-136/abigail/lua/ch-1.lua
index 182d18fba7..1c3e149da6 100644
--- a/challenge-136/abigail/lua/ch-1.lua
+++ b/challenge-136/abigail/lua/ch-1.lua
@@ -13,10 +13,9 @@
 --    (https://en.wikipedia.org/wiki/Euclidean_algorithm#Implementations)
 --
 function gcd (a, b)
-    while b > 0 do
-        a, b = b, a % b
-    end
-    return a
+    if b >  a then return gcd (b, a) end
+    if b == 0 then return a          end
+                   return gcd (b, a % b)
 end
 
 --
diff --git a/challenge-136/abigail/node/ch-1.js b/challenge-136/abigail/node/ch-1.js
index 08331ea39f..1fb04ad1c4 100644
--- a/challenge-136/abigail/node/ch-1.js
+++ b/challenge-136/abigail/node/ch-1.js
@@ -13,10 +13,9 @@
 //    (https://en.wikipedia.org/wiki/Euclidean_algorithm#Implementations)
 //
 function gcd (a, b) {
-    while (b > 0) {
-        [a, b] = [b, a % b]
-    }
-    return (a)
+    if (b >  a) {return gcd (b, a)}
+    if (b == 0) {return a}
+                 return gcd (b, a % b)
 }
 
 //