diff options
Diffstat (limited to 'jni/ruby/benchmark/bm_so_pidigits.rb')
-rw-r--r-- | jni/ruby/benchmark/bm_so_pidigits.rb | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/jni/ruby/benchmark/bm_so_pidigits.rb b/jni/ruby/benchmark/bm_so_pidigits.rb new file mode 100644 index 0000000..c7d6fbf --- /dev/null +++ b/jni/ruby/benchmark/bm_so_pidigits.rb @@ -0,0 +1,92 @@ +# The Great Computer Language Shootout +# http://shootout.alioth.debian.org/ +# +# contributed by Gabriele Renzi + +class PiDigitSpigot + + def initialize() + @z = Transformation.new 1,0,0,1 + @x = Transformation.new 0,0,0,0 + @inverse = Transformation.new 0,0,0,0 + end + + def next! + @y = @z.extract(3) + if safe? @y + @z = produce(@y) + @y + else + @z = consume @x.next!() + next!() + end + end + + def safe?(digit) + digit == @z.extract(4) + end + + def produce(i) + @inverse.qrst(10,-10*i,0,1).compose(@z) + end + + def consume(a) + @z.compose(a) + end +end + + +class Transformation + attr_reader :q, :r, :s, :t + def initialize (q, r, s, t) + @q,@r,@s,@t,@k = q,r,s,t,0 + end + + def next!() + @q = @k = @k + 1 + @r = 4 * @k + 2 + @s = 0 + @t = 2 * @k + 1 + self + end + + def extract(j) + (@q * j + @r) / (@s * j + @t) + end + + def compose(a) + self.class.new( @q * a.q, + @q * a.r + r * a.t, + @s * a.q + t * a.s, + @s * a.r + t * a.t + ) + end + + def qrst *args + initialize *args + self + end + + +end + + +WIDTH = 10 +n = 2_500 # Integer(ARGV[0]) +j = 0 + +digits = PiDigitSpigot.new + +while n > 0 + if n >= WIDTH + WIDTH.times {print digits.next!} + j += WIDTH + else + n.times {print digits.next!} + (WIDTH-n).times {print " "} + j += n + end + puts "\t:"+j.to_s + n -= WIDTH +end + |