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mirror of https://github.com/golang/go synced 2024-11-15 01:50:28 -07:00
go/test/bench/binary-tree.go
Robert Griesemer 45ca9f7a9e 1) Change default gofmt default settings for
parsing and printing to new syntax.

   Use -oldparser to parse the old syntax,
   use -oldprinter to print the old syntax.

2) Change default gofmt formatting settings
   to use tabs for indentation only and to use
   spaces for alignment. This will make the code
   alignment insensitive to an editor's tabwidth.

   Use -spaces=false to use tabs for alignment.

3) Manually changed src/exp/parser/parser_test.go
   so that it doesn't try to parse the parser's
   source files using the old syntax (they have
   new syntax now).

4) gofmt -w src misc test/bench

5th and last set of files.

R=rsc
CC=golang-dev
https://golang.org/cl/180050
2009-12-15 15:41:46 -08:00

93 lines
2.8 KiB
Go

/*
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of "The Computer Language Benchmarks Game" nor the
name of "The Computer Language Shootout Benchmarks" nor the names of
its contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
*/
/* The Computer Language Benchmarks Game
* http://shootout.alioth.debian.org/
*
* contributed by The Go Authors.
* based on C program by Kevin Carson
*/
package main
import (
"flag"
"fmt"
)
var n = flag.Int("n", 15, "depth")
type Node struct {
item int
left, right *Node
}
func bottomUpTree(item, depth int) *Node {
if depth <= 0 {
return &Node{item: item}
}
return &Node{item, bottomUpTree(2*item-1, depth-1), bottomUpTree(2*item, depth-1)}
}
func (n *Node) itemCheck() int {
if n.left == nil {
return n.item
}
return n.item + n.left.itemCheck() - n.right.itemCheck()
}
const minDepth = 4
func main() {
flag.Parse()
maxDepth := *n
if minDepth+2 > *n {
maxDepth = minDepth + 2
}
stretchDepth := maxDepth + 1
check := bottomUpTree(0, stretchDepth).itemCheck()
fmt.Printf("stretch tree of depth %d\t check: %d\n", stretchDepth, check)
longLivedTree := bottomUpTree(0, maxDepth)
for depth := minDepth; depth <= maxDepth; depth += 2 {
iterations := 1 << uint(maxDepth-depth+minDepth)
check = 0
for i := 1; i <= iterations; i++ {
check += bottomUpTree(i, depth).itemCheck()
check += bottomUpTree(-i, depth).itemCheck()
}
fmt.Printf("%d\t trees of depth %d\t check: %d\n", iterations*2, depth, check)
}
fmt.Printf("long lived tree of depth %d\t check: %d\n", maxDepth, longLivedTree.itemCheck())
}