When looping over possible divisors, stop at n / 2.

8 files changed, 8 insertions, 8 deletions

diff --git a/challenge-109/abigail/awk/ch-1.awk b/challenge-109/abigail/awk/ch-1.awk
index 6b889ae3a0..203c7f1fec 100644
--- a/challenge-109/abigail/awk/ch-1.awk
+++ b/challenge-109/abigail/awk/ch-1.awk
@@ -10,7 +10,7 @@
 
 function divisor_sum (n, i) {
     sum = 0
-    for (i = 2; i < n; i ++) {
+    for (i = 2; i <= n / 2; i ++) {
         if (n % i == 0) {
             sum += i
         }
diff --git a/challenge-109/abigail/bash/ch-1.sh b/challenge-109/abigail/bash/ch-1.sh
index de09aa6414..752a4f9760 100644
--- a/challenge-109/abigail/bash/ch-1.sh
+++ b/challenge-109/abigail/bash/ch-1.sh
@@ -16,7 +16,7 @@ function divisor_sum () {
     local n=$1
     sum=0
     local i
-    for ((i = 2; i < n; i ++))
+    for ((i = 2; i <= n / 2; i ++))
     do  if   ((n % i == 0))
         then ((sum += i))
         fi
diff --git a/challenge-109/abigail/c/ch-1.c b/challenge-109/abigail/c/ch-1.c
index e6716c148a..377caf63f3 100644
--- a/challenge-109/abigail/c/ch-1.c
+++ b/challenge-109/abigail/c/ch-1.c
@@ -20,7 +20,7 @@ typedef int number;  /* Change if we want large numbers */
 
 number divisor_sum (number n) {
     number sum = 0;
-    for (number i = 2; i < n; i ++) {
+    for (number i = 2; i <= n / 2; i ++) {
         if (!(n % i)) {
             sum += i;
         }
diff --git a/challenge-109/abigail/lua/ch-1.lua b/challenge-109/abigail/lua/ch-1.lua
index 5eb2d477f9..74c3b7d914 100644
--- a/challenge-109/abigail/lua/ch-1.lua
+++ b/challenge-109/abigail/lua/ch-1.lua
@@ -15,7 +15,7 @@ local COUNT   = 20
 
 function divisor_sum (n)
     local sum = 0
-    for i = 2, n - 2 do
+    for i = 2, n / 2 do
         if   n % i == 0 
         then sum = sum + i
         end
diff --git a/challenge-109/abigail/node/ch-1.js b/challenge-109/abigail/node/ch-1.js
index d7cff7b0f5..0f75cf4962 100644
--- a/challenge-109/abigail/node/ch-1.js
+++ b/challenge-109/abigail/node/ch-1.js
@@ -15,7 +15,7 @@ let COUNT   = 20
 
 function divisor_sum (n) {
     let sum = 0
-    for (let i = 2; i < n; i ++) {
+    for (let i = 2; i <= Math . floor (n / 2); i ++) {
         if (n % i == 0) {
             sum += i
         }
diff --git a/challenge-109/abigail/perl/ch-1.pl b/challenge-109/abigail/perl/ch-1.pl
index 64f21d5d24..967a0344de 100644
--- a/challenge-109/abigail/perl/ch-1.pl
+++ b/challenge-109/abigail/perl/ch-1.pl
@@ -47,5 +47,5 @@ elsif ($type == $TYPE_COMPUTE) {
     # calculate the first 20 numbers, we don't have to care about
     # efficiency.
     #
-    say map {my $n = $_; sum0 grep {!($n % $_)} 2 .. $_ - 1} 1 .. $COUNT;
+    say map {my $n = $_; sum0 grep {!($n % $_)} 2 .. $_ / 2} 1 .. $COUNT;
 }
diff --git a/challenge-109/abigail/python/ch-1.py b/challenge-109/abigail/python/ch-1.py
index 6600bda6d5..f9e51a0897 100644
--- a/challenge-109/abigail/python/ch-1.py
+++ b/challenge-109/abigail/python/ch-1.py
@@ -16,7 +16,7 @@ COMPUTE =  1
 
 def divisor_sum (n):
     sum = 0
-    for i in range (2, n):
+    for i in range (2, n / 2 + 1):
         if n % i == 0:
             sum = sum + i
     return (sum)
diff --git a/challenge-109/abigail/ruby/ch-1.rb b/challenge-109/abigail/ruby/ch-1.rb
index 95a38a69cb..0c73c368dd 100644
--- a/challenge-109/abigail/ruby/ch-1.rb
+++ b/challenge-109/abigail/ruby/ch-1.rb
@@ -15,7 +15,7 @@ COUNT   = 20
 
 def divisor_sum (n)
     sum = 0
-    for i in 2 .. n - 1
+    for i in 2 .. n / 2
         if   n % i == 0
         then sum += i
         end