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authork0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-07-10 13:08:40 (GMT)
committerk0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-07-10 13:08:40 (GMT)
commit433af16167aec949c6345ad41b78b17c440b4a6d (patch)
tree42b9a14817cccef4a57177329381f97a7a2ac75c /benchmark/so_pidigits.rb
parentf992f4251874a025de09ffecf0f2b8cb984f2201 (diff)
benchmark: drop all bm_ prefix for legacy driver.rb
benchmark/*.rb is only benchmarks now. We don't need prefixes. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63928 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'benchmark/so_pidigits.rb')
-rw-r--r--benchmark/so_pidigits.rb92
1 files changed, 92 insertions, 0 deletions
diff --git a/benchmark/so_pidigits.rb b/benchmark/so_pidigits.rb
new file mode 100644
index 0000000..9a537b2
--- /dev/null
+++ b/benchmark/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
+