diff options
Diffstat (limited to 'trunk/benchmark/bm_so_nsieve.rb')
-rw-r--r-- | trunk/benchmark/bm_so_nsieve.rb | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/trunk/benchmark/bm_so_nsieve.rb b/trunk/benchmark/bm_so_nsieve.rb new file mode 100644 index 0000000000..a65cc78233 --- /dev/null +++ b/trunk/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 |