mirror of
https://github.com/golang/go
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96 lines
2.6 KiB
Go
96 lines
2.6 KiB
Go
/*
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of "The Computer Language Benchmarks Game" nor the
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name of "The Computer Language Shootout Benchmarks" nor the names of
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its contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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/* The Computer Language Benchmarks Game
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* http://shootout.alioth.debian.org/
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*
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* contributed by The Go Authors.
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* Based on mandelbrot.c contributed by Greg Buchholz
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*/
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package main
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import (
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"bufio"
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"flag"
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"fmt"
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"os"
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)
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var n = flag.Int("n", 200, "size")
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func main() {
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flag.Parse()
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out := bufio.NewWriter(os.Stdout)
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defer out.Flush()
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w := *n
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h := *n
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bit_num := 0
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byte_acc := byte(0)
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const Iter = 50
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const Zero float64 = 0
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const Limit = 2.0
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fmt.Fprintf(out, "P4\n%d %d\n", w, h)
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for y := 0; y < h; y++ {
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for x := 0; x < w; x++ {
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Zr, Zi, Tr, Ti := Zero, Zero, Zero, Zero
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Cr := (2*float64(x)/float64(w) - 1.5)
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Ci := (2*float64(y)/float64(h) - 1.0)
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for i := 0; i < Iter && (Tr+Ti <= Limit*Limit); i++ {
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Zi = 2*Zr*Zi + Ci
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Zr = Tr - Ti + Cr
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Tr = Zr * Zr
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Ti = Zi * Zi
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}
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byte_acc <<= 1
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if Tr+Ti <= Limit*Limit {
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byte_acc |= 0x01
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}
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bit_num++
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if bit_num == 8 {
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out.WriteByte(byte_acc)
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byte_acc = 0
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bit_num = 0
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} else if x == w-1 {
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byte_acc <<= uint(8 - w%8)
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out.WriteByte(byte_acc)
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byte_acc = 0
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bit_num = 0
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}
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}
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}
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}
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