diff options
author | Rob Pike <r@golang.org> | 2009-08-04 19:38:08 -0700 |
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committer | Rob Pike <r@golang.org> | 2009-08-04 19:38:08 -0700 |
commit | 2f275dfe88e9b6dea79e2e269faf98370f513dd1 (patch) | |
tree | 1b7781ae8925b1d7b8b4e609311fe84967fff674 /test/bench/binary-tree.go | |
parent | 1b34f64196e8248d8538f066934621d0bcaefb90 (diff) | |
download | golang-2f275dfe88e9b6dea79e2e269faf98370f513dd1.tar.gz |
binary tree
R=rsc
DELTA=324 (323 added, 0 deleted, 1 changed)
OCL=32759
CL=32768
Diffstat (limited to 'test/bench/binary-tree.go')
-rw-r--r-- | test/bench/binary-tree.go | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/test/bench/binary-tree.go b/test/bench/binary-tree.go new file mode 100644 index 000000000..030e6acb0 --- /dev/null +++ b/test/bench/binary-tree.go @@ -0,0 +1,93 @@ +/* +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"; + "os"; +) + +var n = flag.Int("n", 20, "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.Println("stretch tree of depth ", stretchDepth, "\t check:", 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.Println(iterations*2, "\t trees of depth ", depth, "\t check: ", check); + } + fmt.Println("long lived tree of depth", maxDepth, "\t check:", longLivedTree.itemCheck()); +} |