diff options
| author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-11-16 01:30:29 +0000 |
|---|---|---|
| committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2007-11-16 01:30:29 +0000 |
| commit | 75feee0968c9345e7ffd2bda9835fcd60b4c0880 (patch) | |
| tree | fa4216d535d8b5dcc45f39c19c64385172e710bf /benchmark/bm_so_nsieve_bits.rb | |
| parent | 501407d3af04a2a7c4b4d49168d512fb89327b6b (diff) | |
* set eol-style.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13944 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'benchmark/bm_so_nsieve_bits.rb')
| -rw-r--r-- | benchmark/bm_so_nsieve_bits.rb | 84 |
1 files changed, 42 insertions, 42 deletions
diff --git a/benchmark/bm_so_nsieve_bits.rb b/benchmark/bm_so_nsieve_bits.rb index 693b2f246d..019b8b6382 100644 --- a/benchmark/bm_so_nsieve_bits.rb +++ b/benchmark/bm_so_nsieve_bits.rb @@ -1,42 +1,42 @@ -#!/usr/bin/ruby
-#
-# The Great Computer Language Shootout
-# http://shootout.alioth.debian.org/
-#
-# nsieve-bits in Ruby
-# Contributed by Glenn Parker, March 2005
-
-CharExponent = 3
-BitsPerChar = 1 << CharExponent
-LowMask = BitsPerChar - 1
-
-def sieve(m)
- items = "\xFF" * ((m / BitsPerChar) + 1)
- masks = ""
- BitsPerChar.times do |b|
- masks << (1 << b).chr
- end
-
- count = 0
- pmax = m - 1
- 2.step(pmax, 1) do |p|
- if items[p >> CharExponent][p & LowMask] == 1
- count += 1
- p.step(pmax, p) do |mult|
- a = mult >> CharExponent
- b = mult & LowMask
- items[a] -= masks[b] if items[a][b] != 0
- end
- end
- end
- count
-end
-
-n = 9 # (ARGV[0] || 2).to_i
-n.step(n - 2, -1) do |exponent|
- break if exponent < 0
- m = 2 ** exponent * 10_000
- count = sieve(m)
- printf "Primes up to %8d %8d\n", m, count
-end
-
+#!/usr/bin/ruby +# +# The Great Computer Language Shootout +# http://shootout.alioth.debian.org/ +# +# nsieve-bits in Ruby +# Contributed by Glenn Parker, March 2005 + +CharExponent = 3 +BitsPerChar = 1 << CharExponent +LowMask = BitsPerChar - 1 + +def sieve(m) + items = "\xFF" * ((m / BitsPerChar) + 1) + masks = "" + BitsPerChar.times do |b| + masks << (1 << b).chr + end + + count = 0 + pmax = m - 1 + 2.step(pmax, 1) do |p| + if items[p >> CharExponent][p & LowMask] == 1 + count += 1 + p.step(pmax, p) do |mult| + a = mult >> CharExponent + b = mult & LowMask + items[a] -= masks[b] if items[a][b] != 0 + end + end + end + count +end + +n = 9 # (ARGV[0] || 2).to_i +n.step(n - 2, -1) do |exponent| + break if exponent < 0 + m = 2 ** exponent * 10_000 + count = sieve(m) + printf "Primes up to %8d %8d\n", m, count +end + |