1 files changed, 14 insertions, 0 deletions
diff --git a/ruby_1_8_6/sample/sieve.rb b/ruby_1_8_6/sample/sieve.rb
new file mode 100644
index 0000000000..e0bb21d640
--- /dev/null
+++ b/ruby_1_8_6/sample/sieve.rb
@@ -0,0 +1,14 @@
+# sieve of Eratosthenes
+max = Integer(ARGV.shift || 100)
+sieve = []
+for i in 2 .. max
+  sieve[i] = i
+end
+
+for i in 2 .. Math.sqrt(max)
+  next unless sieve[i]
+  (i*i).step(max, i) do |j|
+    sieve[j] = nil
+  end
+end
+puts sieve.compact.join(", ")