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authorshyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2007-08-22 01:53:51 +0000
committershyouhei <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2007-08-22 01:53:51 +0000
commit1e760c0be3ed35874204114e7454509f740c0fe2 (patch)
treea75eb2b1eea073830902d1fa49c568c4525c8b57 /ruby_1_8_6/sample/sieve.rb
parenta2055d63b41a6678dc7aeb17d0bece314e700c5a (diff)
add tag v1_8_6_71v1_8_5_71
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v1_8_5_71@13189 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'ruby_1_8_6/sample/sieve.rb')
-rw-r--r--ruby_1_8_6/sample/sieve.rb14
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(", ")