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authorusa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2013-05-14 11:27:23 +0000
committerusa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2013-05-14 11:27:23 +0000
commitaa6e98139c8e1ea442fb2182341aaa08ff55b529 (patch)
treea509eb830418991995bfe3b840d4bf270ff7f0e2 /ruby_1_9_3/benchmark/bm_so_nsieve.rb
parent9e9d191cf367caa17776231a2d0fad0da47b160a (diff)
add tag v1_9_3_426
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v1_9_3_426@40733 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'ruby_1_9_3/benchmark/bm_so_nsieve.rb')
-rw-r--r--ruby_1_9_3/benchmark/bm_so_nsieve.rb35
1 files changed, 35 insertions, 0 deletions
diff --git a/ruby_1_9_3/benchmark/bm_so_nsieve.rb b/ruby_1_9_3/benchmark/bm_so_nsieve.rb
new file mode 100644
index 0000000000..a65cc78233
--- /dev/null
+++ b/ruby_1_9_3/benchmark/bm_so_nsieve.rb
@@ -0,0 +1,35 @@
+# The Computer Language Shootout
+# http://shootout.alioth.debian.org/
+#
+# contributed by Glenn Parker, March 2005
+# modified by Evan Phoenix, Sept 2006
+
+def sieve(m)
+ flags = Flags.dup[0,m]
+ count = 0
+ pmax = m - 1
+ p = 2
+ while p <= pmax
+ unless flags[p].zero?
+ count += 1
+ mult = p
+ while mult <= pmax
+ flags[mult] = 0
+ mult += p
+ end
+ end
+ p += 1
+ end
+ count
+end
+
+n = 9 # (ARGV[0] || 2).to_i
+Flags = ("\x1" * ( 2 ** n * 10_000)).unpack("c*")
+
+n.downto(n-2) do |exponent|
+ break if exponent < 0
+ m = (1 << exponent) * 10_000
+ # m = (2 ** exponent) * 10_000
+ count = sieve(m)
+ printf "Primes up to %8d %8d\n", m, count
+end